Java tutorial
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.nio.CharBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @author yonik
* @version $Id$
*/
public class ObjectBuilder {
public static Object fromJSON(String json) throws IOException {
JSONParser p = new JSONParser(json);
return getVal(p);
}
public static Object getVal(JSONParser parser) throws IOException {
return new ObjectBuilder(parser).getVal();
}
final JSONParser parser;
public ObjectBuilder(JSONParser parser) throws IOException {
this.parser = parser;
if (parser.lastEvent() == 0)
parser.nextEvent();
}
public Object getVal() throws IOException {
int ev = parser.lastEvent();
switch (ev) {
case JSONParser.STRING:
return getString();
case JSONParser.LONG:
return getLong();
case JSONParser.NUMBER:
return getNumber();
case JSONParser.BIGNUMBER:
return getBigNumber();
case JSONParser.BOOLEAN:
return getBoolean();
case JSONParser.NULL:
return getNull();
case JSONParser.OBJECT_START:
return getObject();
case JSONParser.OBJECT_END:
return null; // OR ERROR?
case JSONParser.ARRAY_START:
return getArray();
case JSONParser.ARRAY_END:
return null; // OR ERROR?
case JSONParser.EOF:
return null; // OR ERROR?
default:
return null; // OR ERROR?
}
}
public Object getString() throws IOException {
return parser.getString();
}
public Object getLong() throws IOException {
return Long.valueOf(parser.getLong());
}
public Object getNumber() throws IOException {
CharArr num = parser.getNumberChars();
String numstr = num.toString();
double d = Double.parseDouble(numstr);
if (!Double.isInfinite(d))
return Double.valueOf(d);
// TODO: use more efficient constructor in Java5
return new BigDecimal(numstr);
}
public Object getBigNumber() throws IOException {
CharArr num = parser.getNumberChars();
String numstr = num.toString();
for (int ch; (ch = num.read()) != -1;) {
if (ch == '.' || ch == 'e' || ch == 'E')
return new BigDecimal(numstr);
}
return new BigInteger(numstr);
}
public Object getBoolean() throws IOException {
return parser.getBoolean();
}
public Object getNull() throws IOException {
parser.getNull();
return null;
}
public Object newObject() throws IOException {
return new LinkedHashMap();
}
public Object getKey() throws IOException {
return parser.getString();
}
public void addKeyVal(Object map, Object key, Object val) throws IOException {
Object prev = ((Map) map).put(key, val);
// TODO: test for repeated value?
}
public Object objectEnd(Object obj) {
return obj;
}
public Object getObject() throws IOException {
Object m = newObject();
for (;;) {
int ev = parser.nextEvent();
if (ev == JSONParser.OBJECT_END)
return objectEnd(m);
Object key = getKey();
ev = parser.nextEvent();
Object val = getVal();
addKeyVal(m, key, val);
}
}
public Object newArray() {
return new ArrayList();
}
public void addArrayVal(Object arr, Object val) throws IOException {
((List) arr).add(val);
}
public Object endArray(Object arr) {
return arr;
}
public Object getArray() throws IOException {
Object arr = newArray();
for (;;) {
int ev = parser.nextEvent();
if (ev == JSONParser.ARRAY_END)
return endArray(arr);
Object val = getVal();
addArrayVal(arr, val);
}
}
}
/**
* @author yonik
* @version $Id: JSONParser.java 730138 2008-12-30 14:54:53Z yonik $
*/
class JSONParser {
/** Event indicating a JSON string value, including member names of objects */
public static final int STRING = 1;
/**
* Event indicating a JSON number value which fits into a signed 64 bit
* integer
*/
public static final int LONG = 2;
/**
* Event indicating a JSON number value which has a fractional part or an
* exponent and with string length <= 23 chars not including sign. This covers
* all representations of normal values for Double.toString().
*/
public static final int NUMBER = 3;
/**
* Event indicating a JSON number value that was not produced by toString of
* any Java primitive numerics such as Double or Long. It is either an integer
* outside the range of a 64 bit signed integer, or a floating point value
* with a string representation of more than 23 chars.
*/
public static final int BIGNUMBER = 4;
/** Event indicating a JSON boolean */
public static final int BOOLEAN = 5;
/** Event indicating a JSON null */
public static final int NULL = 6;
/** Event indicating the start of a JSON object */
public static final int OBJECT_START = 7;
/** Event indicating the end of a JSON object */
public static final int OBJECT_END = 8;
/** Event indicating the start of a JSON array */
public static final int ARRAY_START = 9;
/** Event indicating the end of a JSON array */
public static final int ARRAY_END = 10;
/** Event indicating the end of input has been reached */
public static final int EOF = 11;
public static String getEventString(int e) {
switch (e) {
case STRING:
return "STRING";
case LONG:
return "LONG";
case NUMBER:
return "NUMBER";
case BIGNUMBER:
return "BIGNUMBER";
case BOOLEAN:
return "BOOLEAN";
case NULL:
return "NULL";
case OBJECT_START:
return "OBJECT_START";
case OBJECT_END:
return "OBJECT_END";
case ARRAY_START:
return "ARRAY_START";
case ARRAY_END:
return "ARRAY_END";
case EOF:
return "EOF";
}
return "Unknown: " + e;
}
private static final CharArr devNull = new NullCharArr();
final char[] buf; // input buffer with JSON text in it
int start; // current position in the buffer
int end; // end position in the buffer (one past last valid index)
final Reader in; // optional reader to obtain data from
boolean eof = false; // true if the end of the stream was reached.
long gpos; // global position = gpos + start
int event; // last event read
public JSONParser(Reader in) {
this(in, new char[8192]);
// 8192 matches the default buffer size of a BufferedReader so double
// buffering of the data is avoided.
}
public JSONParser(Reader in, char[] buffer) {
this.in = in;
this.buf = buffer;
}
// idea - if someone passes us a CharArrayReader, we could
// directly use that buffer as it's protected.
public JSONParser(char[] data, int start, int end) {
this.in = null;
this.buf = data;
this.start = start;
this.end = end;
}
public JSONParser(String data) {
this(data, 0, data.length());
}
public JSONParser(String data, int start, int end) {
this.in = null;
this.start = start;
this.end = end;
this.buf = new char[end - start];
data.getChars(start, end, buf, 0);
}
// temporary output buffer
private final CharArr out = new CharArr(64);
// We need to keep some state in order to (at a minimum) know if
// we should skip ',' or ':'.
private byte[] stack = new byte[16];
private int ptr = 0; // pointer into the stack of parser states
private byte state = 0; // current parser state
// parser states stored in the stack
private static final byte DID_OBJSTART = 1; // '{' just read
private static final byte DID_ARRSTART = 2; // '[' just read
private static final byte DID_ARRELEM = 3; // array element just read
private static final byte DID_MEMNAME = 4; // object member name (map key)
// just read
private static final byte DID_MEMVAL = 5; // object member value (map val)
// just read
// info about value that was just read (or is in the middle of being read)
private int valstate;
// push current parser state (use at start of new container)
private final void push() {
if (ptr >= stack.length) {
// doubling here is probably overkill, but anything that needs to double
// more than
// once (32 levels deep) is very atypical anyway.
byte[] newstack = new byte[stack.length << 1];
System.arraycopy(stack, 0, newstack, 0, stack.length);
stack = newstack;
}
stack[ptr++] = state;
}
// pop parser state (use at end of container)
private final void pop() {
if (--ptr < 0) {
throw err("Unbalanced container");
} else {
state = stack[ptr];
}
}
protected void fill() throws IOException {
if (in != null) {
gpos += end;
start = 0;
int num = in.read(buf, 0, buf.length);
end = num >= 0 ? num : 0;
}
if (start >= end)
eof = true;
}
private void getMore() throws IOException {
fill();
if (start >= end) {
throw err(null);
}
}
protected int getChar() throws IOException {
if (start >= end) {
fill();
if (start >= end)
return -1;
}
return buf[start++];
}
private int getCharNWS() throws IOException {
for (;;) {
int ch = getChar();
if (!(ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r'))
return ch;
}
}
private void expect(char[] arr) throws IOException {
for (int i = 1; i < arr.length; i++) {
int ch = getChar();
if (ch != arr[i]) {
if (ch == -1)
throw new RuntimeException("Unexpected EOF");
throw new RuntimeException("Expected " + new String(arr));
}
}
}
private RuntimeException err(String msg) {
// We can't tell if EOF was hit by comparing start<=end
// because the illegal char could have been the last in the buffer
// or in the stream. To deal with this, the "eof" var was introduced
if (!eof && start > 0)
start--; // backup one char
String chs = "char=" + ((start >= end) ? "(EOF)" : "" + (char) buf[start]);
String pos = "position=" + (gpos + start);
String tot = chs + ',' + pos;
if (msg == null) {
if (start >= end)
msg = "Unexpected EOF";
else
msg = "JSON Parse Error";
}
return new RuntimeException(msg + ": " + tot);
}
private boolean bool; // boolean value read
private long lval; // long value read
private int nstate; // current state while reading a number
private static final int HAS_FRACTION = 0x01; // nstate flag, '.' already read
private static final int HAS_EXPONENT = 0x02; // nstate flag, '[eE][+-]?[0-9]'
// already read
/**
* Returns the long read... only significant if valstate==LONG after this
* call. firstChar should be the first numeric digit read.
*/
private long readNumber(int firstChar, boolean isNeg) throws IOException {
out.unsafeWrite(firstChar); // unsafe OK since we know output is big enough
// We build up the number in the negative plane since it's larger (by one)
// than
// the positive plane.
long v = '0' - firstChar;
for (int i = 0; i < 22; i++) {
int ch = getChar();
// TODO: is this switch faster as an if-then-else?
switch (ch) {
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
v = v * 10 - (ch - '0');
out.unsafeWrite(ch);
continue;
case '.':
out.unsafeWrite('.');
valstate = readFrac(out, 22 - i);
return 0;
case 'e':
case 'E':
out.unsafeWrite(ch);
nstate = 0;
valstate = readExp(out, 22 - i);
return 0;
default:
// return the number, relying on nextEvent() to return an error
// for invalid chars following the number.
if (ch != -1)
--start; // push back last char if not EOF
// the max number of digits we are reading only allows for
// a long to wrap once, so we can just check if the sign is
// what is expected to detect an overflow.
if (isNeg) {
// -0 is allowed by the spec
valstate = v <= 0 ? LONG : BIGNUMBER;
} else {
v = -v;
valstate = v >= 0 ? LONG : BIGNUMBER;
}
return v;
}
}
nstate = 0;
valstate = BIGNUMBER;
return 0;
}
// read digits right of decimal point
private int readFrac(CharArr arr, int lim) throws IOException {
nstate = HAS_FRACTION; // deliberate set instead of '|'
while (--lim >= 0) {
int ch = getChar();
if (ch >= '0' && ch <= '9') {
arr.write(ch);
} else if (ch == 'e' || ch == 'E') {
arr.write(ch);
return readExp(arr, lim);
} else {
if (ch != -1)
start--; // back up
return NUMBER;
}
}
return BIGNUMBER;
}
// call after 'e' or 'E' has been seen to read the rest of the exponent
private int readExp(CharArr arr, int lim) throws IOException {
nstate |= HAS_EXPONENT;
int ch = getChar();
lim--;
if (ch == '+' || ch == '-') {
arr.write(ch);
ch = getChar();
lim--;
}
// make sure at least one digit is read.
if (ch < '0' || ch > '9') {
throw err("missing exponent number");
}
arr.write(ch);
return readExpDigits(arr, lim);
}
// continuation of readExpStart
private int readExpDigits(CharArr arr, int lim) throws IOException {
while (--lim >= 0) {
int ch = getChar();
if (ch >= '0' && ch <= '9') {
arr.write(ch);
} else {
if (ch != -1)
start--; // back up
return NUMBER;
}
}
return BIGNUMBER;
}
private void continueNumber(CharArr arr) throws IOException {
if (arr != out)
arr.write(out);
if ((nstate & HAS_EXPONENT) != 0) {
readExpDigits(arr, Integer.MAX_VALUE);
return;
}
if (nstate != 0) {
readFrac(arr, Integer.MAX_VALUE);
return;
}
for (;;) {
int ch = getChar();
if (ch >= '0' && ch <= '9') {
arr.write(ch);
} else if (ch == '.') {
arr.write(ch);
readFrac(arr, Integer.MAX_VALUE);
return;
} else if (ch == 'e' || ch == 'E') {
arr.write(ch);
readExp(arr, Integer.MAX_VALUE);
return;
} else {
if (ch != -1)
start--;
return;
}
}
}
private int hexval(int hexdig) {
if (hexdig >= '0' && hexdig <= '9') {
return hexdig - '0';
} else if (hexdig >= 'A' && hexdig <= 'F') {
return hexdig + (10 - 'A');
} else if (hexdig >= 'a' && hexdig <= 'f') {
return hexdig + (10 - 'a');
}
throw err("invalid hex digit");
}
// backslash has already been read when this is called
private char readEscapedChar() throws IOException {
switch (getChar()) {
case '"':
return '"';
case '\\':
return '\\';
case '/':
return '/';
case 'n':
return '\n';
case 'r':
return '\r';
case 't':
return '\t';
case 'f':
return '\f';
case 'b':
return '\b';
case 'u':
return (char) ((hexval(getChar()) << 12) | (hexval(getChar()) << 8) | (hexval(getChar()) << 4)
| (hexval(getChar())));
}
throw err("Invalid character escape in string");
}
// a dummy buffer we can use to point at other buffers
private final CharArr tmp = new CharArr(null, 0, 0);
private CharArr readStringChars() throws IOException {
char c = 0;
int i;
for (i = start; i < end; i++) {
c = buf[i];
if (c == '"') {
tmp.set(buf, start, i); // directly use input buffer
start = i + 1; // advance past last '"'
return tmp;
} else if (c == '\\') {
break;
}
}
out.reset();
readStringChars2(out, i);
return out;
}
// middle is the pointer to the middle of a buffer to start scanning for a
// non-string
// character ('"' or "/"). start<=middle<end
// this should be faster for strings with fewer escapes, but probably slower
// for many escapes.
private void readStringChars2(CharArr arr, int middle) throws IOException {
for (;;) {
if (middle >= end) {
arr.write(buf, start, middle - start);
getMore();
middle = start;
}
int ch = buf[middle++];
if (ch == '"') {
int len = middle - start - 1;
if (len > 0)
arr.write(buf, start, len);
start = middle;
return;
} else if (ch == '\\') {
int len = middle - start - 1;
if (len > 0)
arr.write(buf, start, len);
start = middle;
arr.write(readEscapedChar());
middle = start;
}
}
}
/*****************************************************************************
* * alternate implelentation // middle is the pointer to the middle of a
* buffer to start scanning for a non-string // character ('"' or "/"). start<=middle<end
* private void readStringChars2a(CharArr arr, int middle) throws IOException {
* int ch=0; for(;;) { // find the next non-string char for (; middle<end;
* middle++) { ch = buf[middle]; if (ch=='"' || ch=='\\') break; }
*
* arr.write(buf,start,middle-start); if (middle>=end) { getMore();
* middle=start; } else { start = middle+1; // set buffer pointer to correct
* spot if (ch=='"') { valstate=0; return; } else if (ch=='\\') {
* arr.write(readEscapedChar()); if (start>=end) getMore(); middle=start; } } } }
****************************************************************************/
// return the next event when parser is in a neutral state (no
// map separators or array element separators to read
private int next(int ch) throws IOException {
for (;;) {
switch (ch) {
case ' ':
case '\t':
break;
case '\r':
case '\n':
break; // try and keep track of linecounts?
case '"':
valstate = STRING;
return STRING;
case '{':
push();
state = DID_OBJSTART;
return OBJECT_START;
case '[':
push();
state = DID_ARRSTART;
return ARRAY_START;
case '0':
out.reset();
// special case '0'? If next char isn't '.' val=0
ch = getChar();
if (ch == '.') {
start--;
ch = '0';
readNumber('0', false);
return valstate;
} else if (ch > '9' || ch < '0') {
out.unsafeWrite('0');
start--;
lval = 0;
valstate = LONG;
return LONG;
} else {
throw err("Leading zeros not allowed");
}
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
out.reset();
lval = readNumber(ch, false);
return valstate;
case '-':
out.reset();
out.unsafeWrite('-');
ch = getChar();
if (ch < '0' || ch > '9')
throw err("expected digit after '-'");
lval = readNumber(ch, true);
return valstate;
case 't':
valstate = BOOLEAN;
// TODO: test performance of this non-branching inline version.
// if ((('r'-getChar())|('u'-getChar())|('e'-getChar())) != 0) err("");
expect(JSONUtil.TRUE_CHARS);
bool = true;
return BOOLEAN;
case 'f':
valstate = BOOLEAN;
expect(JSONUtil.FALSE_CHARS);
bool = false;
return BOOLEAN;
case 'n':
valstate = NULL;
expect(JSONUtil.NULL_CHARS);
return NULL;
case -1:
if (getLevel() > 0)
throw new RuntimeException("Premature EOF");
return EOF;
default:
throw err(null);
}
ch = getChar();
}
}
public String toString() {
return "start=" + start + ",end=" + end + ",state=" + state + "valstate=" + valstate;
}
/**
* Returns the next event encountered in the JSON stream, one of
* <ul>
* <li>{@link #STRING}</li>
* <li>{@link #LONG}</li>
* <li>{@link #NUMBER}</li>
* <li>{@link #BIGNUMBER}</li>
* <li>{@link #BOOLEAN}</li>
* <li>{@link #NULL}</li>
* <li>{@link #OBJECT_START}</li>
* <li>{@link #OBJECT_END}</li>
* <li>{@link #OBJECT_END}</li>
* <li>{@link #ARRAY_START}</li>
* <li>{@link #ARRAY_END}</li>
* <li>{@link #EOF}</li>
* </ul>
*/
public int nextEvent() throws IOException {
if (valstate == STRING) {
readStringChars2(devNull, start);
} else if (valstate == BIGNUMBER) {
continueNumber(devNull);
}
valstate = 0;
int ch; // TODO: factor out getCharNWS() to here and check speed
switch (state) {
case 0:
return event = next(getCharNWS());
case DID_OBJSTART:
ch = getCharNWS();
if (ch == '}') {
pop();
return event = OBJECT_END;
}
if (ch != '"') {
throw err("Expected string");
}
state = DID_MEMNAME;
valstate = STRING;
return event = STRING;
case DID_MEMNAME:
ch = getCharNWS();
if (ch != ':') {
throw err("Expected key,value separator ':'");
}
state = DID_MEMVAL; // set state first because it might be pushed...
return event = next(getChar());
case DID_MEMVAL:
ch = getCharNWS();
if (ch == '}') {
pop();
return event = OBJECT_END;
} else if (ch != ',') {
throw err("Expected ',' or '}'");
}
ch = getCharNWS();
if (ch != '"') {
throw err("Expected string");
}
state = DID_MEMNAME;
valstate = STRING;
return event = STRING;
case DID_ARRSTART:
ch = getCharNWS();
if (ch == ']') {
pop();
return event = ARRAY_END;
}
state = DID_ARRELEM; // set state first, might be pushed...
return event = next(ch);
case DID_ARRELEM:
ch = getCharNWS();
if (ch == ']') {
pop();
return event = ARRAY_END;
} else if (ch != ',') {
throw err("Expected ',' or ']'");
}
// state = DID_ARRELEM;
return event = next(getChar());
}
return 0;
}
public int lastEvent() {
return event;
}
public boolean wasKey() {
return state == DID_MEMNAME;
}
private void goTo(int what) throws IOException {
if (valstate == what) {
valstate = 0;
return;
}
if (valstate == 0) {
int ev = nextEvent(); // TODO
if (valstate != what) {
throw err("type mismatch");
}
valstate = 0;
} else {
throw err("type mismatch");
}
}
/** Returns the JSON string value, decoding any escaped characters. */
public String getString() throws IOException {
return getStringChars().toString();
}
/**
* Returns the characters of a JSON string value, decoding any escaped
* characters. <p/>The underlying buffer of the returned <code>CharArr</code>
* should *not* be modified as it may be shared with the input buffer. <p/>The
* returned <code>CharArr</code> will only be valid up until the next
* JSONParser method is called. Any required data should be read before that
* point.
*/
public CharArr getStringChars() throws IOException {
goTo(STRING);
return readStringChars();
}
/** Reads a JSON string into the output, decoding any escaped characters. */
public void getString(CharArr output) throws IOException {
goTo(STRING);
readStringChars2(output, start);
}
/**
* Reads a number from the input stream and parses it as a long, only if the
* value will in fact fit into a signed 64 bit integer.
*/
public long getLong() throws IOException {
goTo(LONG);
return lval;
}
/** Reads a number from the input stream and parses it as a double */
public double getDouble() throws IOException {
return Double.parseDouble(getNumberChars().toString());
}
/**
* Returns the characters of a JSON numeric value. <p/>The underlying buffer
* of the returned <code>CharArr</code> should *not* be modified as it may
* be shared with the input buffer. <p/>The returned <code>CharArr</code>
* will only be valid up until the next JSONParser method is called. Any
* required data should be read before that point.
*/
public CharArr getNumberChars() throws IOException {
int ev = 0;
if (valstate == 0)
ev = nextEvent();
if (valstate == LONG || valstate == NUMBER) {
valstate = 0;
return out;
} else if (valstate == BIGNUMBER) {
continueNumber(out);
valstate = 0;
return out;
} else {
throw err("Unexpected " + ev);
}
}
/** Reads a JSON numeric value into the output. */
public void getNumberChars(CharArr output) throws IOException {
int ev = 0;
if (valstate == 0)
ev = nextEvent();
if (valstate == LONG || valstate == NUMBER)
output.write(this.out);
else if (valstate == BIGNUMBER) {
continueNumber(output);
} else {
throw err("Unexpected " + ev);
}
valstate = 0;
}
/** Reads a boolean value */
public boolean getBoolean() throws IOException {
goTo(BOOLEAN);
return bool;
}
/** Reads a null value */
public void getNull() throws IOException {
goTo(NULL);
}
/**
* @return the current nesting level, the number of parent objects or arrays.
*/
public int getLevel() {
return ptr;
}
public long getPosition() {
return gpos + start;
}
}
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with this
* work for additional information regarding copyright ownership. The ASF
* licenses this file to You under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
// CharArr origins
// V1.0 7/06/97
// V1.1 9/21/99
// V1.2 2/02/04 // Java5 features
// V1.3 11/26/06 // Make safe for Java 1.4, work into Noggit
// @author yonik
// Java5 version could look like the following:
// public class CharArr implements CharSequence, Appendable, Readable, Closeable
// {
/**
* @author yonik
* @version $Id: CharArr.java 583538 2007-10-10 16:53:02Z yonik $
*/
class CharArr implements CharSequence, Appendable {
protected char[] buf;
protected int start;
protected int end;
public CharArr() {
this(32);
}
public CharArr(int size) {
buf = new char[size];
}
public CharArr(char[] arr, int start, int end) {
set(arr, start, end);
}
public void setStart(int start) {
this.start = start;
}
public void setEnd(int end) {
this.end = end;
}
public void set(char[] arr, int start, int end) {
this.buf = arr;
this.start = start;
this.end = end;
}
public char[] getArray() {
return buf;
}
public int getStart() {
return start;
}
public int getEnd() {
return end;
}
public int size() {
return end - start;
}
public int length() {
return size();
}
public int capacity() {
return buf.length;
}
public char charAt(int index) {
return buf[start + index];
}
public CharArr subSequence(int start, int end) {
return new CharArr(buf, this.start + start, this.start + end);
}
public int read() throws IOException {
if (start >= end)
return -1;
return buf[start++];
}
public int read(char cbuf[], int off, int len) {
// TODO
return 0;
}
public void unsafeWrite(char b) {
buf[end++] = b;
}
public void unsafeWrite(int b) {
unsafeWrite((char) b);
}
public void unsafeWrite(char b[], int off, int len) {
System.arraycopy(b, off, buf, end, len);
end += len;
}
protected void resize(int len) {
char newbuf[] = new char[Math.max(buf.length << 1, len)];
System.arraycopy(buf, start, newbuf, 0, size());
buf = newbuf;
}
public void reserve(int num) {
if (end + num > buf.length)
resize(end + num);
}
public void write(char b) {
if (end >= buf.length) {
resize(end + 1);
}
unsafeWrite(b);
}
public final void write(int b) {
write((char) b);
}
public final void write(char[] b) {
write(b, 0, b.length);
}
public void write(char b[], int off, int len) {
reserve(len);
unsafeWrite(b, off, len);
}
public final void write(CharArr arr) {
write(arr.buf, start, end - start);
}
public final void write(String s) {
write(s, 0, s.length());
}
public void write(String s, int stringOffset, int len) {
reserve(len);
s.getChars(stringOffset, len, buf, end);
end += len;
}
public void flush() {
}
public final void reset() {
start = end = 0;
}
public void close() {
}
public char[] toCharArray() {
char newbuf[] = new char[size()];
System.arraycopy(buf, start, newbuf, 0, size());
return newbuf;
}
public String toString() {
return new String(buf, start, size());
}
public int read(CharBuffer cb) throws IOException {
/***************************************************************************
* int sz = size(); if (sz<=0) return -1; if (sz>0) cb.put(buf, start, sz);
* return -1;
**************************************************************************/
int sz = size();
if (sz > 0)
cb.put(buf, start, sz);
start = end;
while (true) {
fill();
int s = size();
if (s == 0)
return sz == 0 ? -1 : sz;
sz += s;
cb.put(buf, start, s);
}
}
public int fill() throws IOException {
return 0; // or -1?
}
// ////////////// Appendable methods /////////////
public final Appendable append(CharSequence csq) throws IOException {
return append(csq, 0, csq.length());
}
public Appendable append(CharSequence csq, int start, int end) throws IOException {
write(csq.subSequence(start, end).toString());
return null;
}
public final Appendable append(char c) throws IOException {
write(c);
return this;
}
}
class NullCharArr extends CharArr {
public NullCharArr() {
super(new char[1], 0, 0);
}
public void unsafeWrite(char b) {
}
public void unsafeWrite(char b[], int off, int len) {
}
public void unsafeWrite(int b) {
}
public void write(char b) {
}
public void write(char b[], int off, int len) {
}
public void reserve(int num) {
}
protected void resize(int len) {
}
public Appendable append(CharSequence csq, int start, int end) throws IOException {
return this;
}
public char charAt(int index) {
return 0;
}
public void write(String s, int stringOffset, int len) {
}
}
// IDEA: a subclass that refills the array from a reader?
class CharArrReader extends CharArr {
protected final Reader in;
public CharArrReader(Reader in, int size) {
super(size);
this.in = in;
}
public int read() throws IOException {
if (start >= end)
fill();
return start >= end ? -1 : buf[start++];
}
public int read(CharBuffer cb) throws IOException {
// empty the buffer and then read direct
int sz = size();
if (sz > 0)
cb.put(buf, start, end);
int sz2 = in.read(cb);
if (sz2 >= 0)
return sz + sz2;
return sz > 0 ? sz : -1;
}
public int fill() throws IOException {
if (start >= end) {
reset();
} else if (start > 0) {
System.arraycopy(buf, start, buf, 0, size());
end = size();
start = 0;
}
/***************************************************************************
* // fill fully or not??? do { int sz = in.read(buf,end,buf.length-end); if
* (sz==-1) return; end+=sz; } while (end < buf.length);
**************************************************************************/
int sz = in.read(buf, end, buf.length - end);
if (sz > 0)
end += sz;
return sz;
}
}
class CharArrWriter extends CharArr {
protected Writer sink;
@Override
public void flush() {
try {
sink.write(buf, start, end - start);
} catch (IOException e) {
throw new RuntimeException(e);
}
start = end = 0;
}
@Override
public void write(char b) {
if (end >= buf.length) {
flush();
}
unsafeWrite(b);
}
@Override
public void write(char b[], int off, int len) {
int space = buf.length - end;
if (len < space) {
unsafeWrite(b, off, len);
} else if (len < buf.length) {
unsafeWrite(b, off, space);
flush();
unsafeWrite(b, off + space, len - space);
} else {
flush();
try {
sink.write(b, off, len);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
@Override
public void write(String s, int stringOffset, int len) {
int space = buf.length - end;
if (len < space) {
s.getChars(stringOffset, stringOffset + len, buf, end);
end += len;
} else if (len < buf.length) {
// if the data to write is small enough, buffer it.
s.getChars(stringOffset, stringOffset + space, buf, end);
flush();
s.getChars(stringOffset + space, stringOffset + len, buf, 0);
end = len - space;
} else {
flush();
// don't buffer, just write to sink
try {
sink.write(s, stringOffset, len);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
}
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with this
* work for additional information regarding copyright ownership. The ASF
* licenses this file to You under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
/**
* @author yonik
* @version $Id: JSONUtil.java 666240 2008-06-10 18:00:38Z yonik $
*/
class JSONUtil {
public static final char[] TRUE_CHARS = new char[] { 't', 'r', 'u', 'e' };
public static final char[] FALSE_CHARS = new char[] { 'f', 'a', 'l', 's', 'e' };
public static final char[] NULL_CHARS = new char[] { 'n', 'u', 'l', 'l' };
public static final char[] HEX_CHARS = new char[] { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b',
'c', 'd', 'e', 'f' };
public static final char VALUE_SEPARATOR = ',';
public static final char NAME_SEPARATOR = ':';
public static final char OBJECT_START = '{';
public static final char OBJECT_END = '}';
public static final char ARRAY_START = '[';
public static final char ARRAY_END = ']';
public static String toJSON(Object o) {
CharArr out = new CharArr();
new TextSerializer().serialize(new JSONWriter(out), o);
return out.toString();
}
public static void writeNumber(long number, CharArr out) {
out.write(Long.toString(number));
}
public static void writeNumber(double number, CharArr out) {
out.write(Double.toString(number));
}
public static void writeString(CharArr val, CharArr out) {
writeString(val.getArray(), val.getStart(), val.getEnd(), out);
}
public static void writeString(char[] val, int start, int end, CharArr out) {
out.write('"');
writeStringPart(val, start, end, out);
out.write('"');
}
public static void writeString(CharSequence val, int start, int end, CharArr out) {
out.write('"');
writeStringPart(val, start, end, out);
out.write('"');
}
public static void writeStringPart(char[] val, int start, int end, CharArr out) {
for (int i = start; i < end; i++) {
char ch = val[i];
switch (ch) {
case '"':
case '\\':
out.write('\\');
out.write(ch);
break;
case '\r':
out.write('\\');
out.write('r');
break;
case '\n':
out.write('\\');
out.write('n');
break;
case '\t':
out.write('\\');
out.write('t');
break;
case '\b':
out.write('\\');
out.write('b');
break;
case '\f':
out.write('\\');
out.write('f');
break;
// case '/':
default:
if (ch <= 0x1F) {
unicodeEscape(ch, out);
} else {
out.write(ch);
}
}
}
}
public static void writeStringPart(CharSequence chars, int start, int end, CharArr out) {
for (int i = start; i < end; i++) {
char ch = chars.charAt(i);
switch (ch) {
case '"':
case '\\':
out.write('\\');
out.write(ch);
break;
case '\r':
out.write('\\');
out.write('r');
break;
case '\n':
out.write('\\');
out.write('n');
break;
case '\t':
out.write('\\');
out.write('t');
break;
case '\b':
out.write('\\');
out.write('b');
break;
case '\f':
out.write('\\');
out.write('f');
break;
// case '/':
default:
if (ch <= 0x1F) {
unicodeEscape(ch, out);
} else {
out.write(ch);
}
}
}
}
public static void unicodeEscape(int ch, CharArr out) {
out.write('\\');
out.write('u');
out.write(HEX_CHARS[ch >>> 12]);
out.write(HEX_CHARS[(ch >>> 8) & 0xf]);
out.write(HEX_CHARS[(ch >>> 4) & 0xf]);
out.write(HEX_CHARS[ch & 0xf]);
}
public static void writeNull(CharArr out) {
out.write(NULL_CHARS);
}
public static void writeBoolean(boolean val, CharArr out) {
out.write(val ? TRUE_CHARS : FALSE_CHARS);
}
}
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with this
* work for additional information regarding copyright ownership. The ASF
* licenses this file to You under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
class TextSerializer {
public void serialize(TextWriter writer, Map val) {
writer.startObject();
boolean first = true;
for (Map.Entry entry : (Set<Map.Entry>) val.entrySet()) {
if (first) {
first = false;
} else {
writer.writeValueSeparator();
}
writer.writeString(entry.getKey().toString());
writer.writeNameSeparator();
serialize(writer, entry.getValue());
}
writer.endObject();
}
public void serialize(TextWriter writer, Collection val) {
writer.startArray();
boolean first = true;
for (Object o : val) {
if (first) {
first = false;
} else {
writer.writeValueSeparator();
}
serialize(writer, o);
}
writer.endArray();
}
public void serialize(TextWriter writer, Object o) {
if (o == null) {
writer.writeNull();
} else if (o instanceof CharSequence) {
writer.writeString((CharSequence) o);
} else if (o instanceof Number) {
if (o instanceof Integer || o instanceof Long) {
writer.write(((Number) o).longValue());
} else if (o instanceof Float || o instanceof Double) {
writer.write(((Number) o).doubleValue());
} else {
CharArr arr = new CharArr();
arr.write(o.toString());
writer.writeNumber(arr);
}
} else if (o instanceof Map) {
this.serialize(writer, (Map) o);
} else if (o instanceof Collection) {
this.serialize(writer, (Collection) o);
} else if (o instanceof Object[]) {
this.serialize(writer, Arrays.asList(o));
} else {
writer.writeString(o.toString());
}
}
}
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with this
* work for additional information regarding copyright ownership. The ASF
* licenses this file to You under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
/**
* @author yonik
* @version $Id: TextWriter.java 666240 2008-06-10 18:00:38Z yonik $
*/
abstract class TextWriter {
public abstract void writeNull();
public abstract void writeString(CharSequence str);
public abstract void writeString(CharArr str);
public abstract void writeStringStart();
public abstract void writeStringChars(CharArr partialStr);
public abstract void writeStringEnd();
public abstract void write(long number);
public abstract void write(double number);
public abstract void write(boolean bool);
public abstract void writeNumber(CharArr digits);
public abstract void writePartialNumber(CharArr digits);
public abstract void startObject();
public abstract void endObject();
public abstract void startArray();
public abstract void endArray();
public abstract void writeValueSeparator();
public abstract void writeNameSeparator();
// void writeNameValue(String name, Object val)?
}
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with this
* work for additional information regarding copyright ownership. The ASF
* licenses this file to You under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
/**
* @author yonik
* @version $Id: JSONWriter.java 666240 2008-06-10 18:00:38Z yonik $
*/
// how to couple with JSONParser to allow streaming large values from input to
// output?
// IDEA 1) have JSONParser.getString(JSONWriter out)?
// IDEA 2) have an output CharArr that acts as a filter to escape data
// IDEA: a subclass of JSONWriter could provide more state and stricter checking
class JSONWriter extends TextWriter {
int level;
boolean doIndent;
final CharArr out;
JSONWriter(CharArr out) {
this.out = out;
}
public void writeNull() {
JSONUtil.writeNull(out);
}
public void writeString(CharSequence str) {
JSONUtil.writeString(str, 0, str.length(), out);
}
public void writeString(CharArr str) {
JSONUtil.writeString(str, out);
}
public void writeStringStart() {
out.write('"');
}
public void writeStringChars(CharArr partialStr) {
JSONUtil.writeStringPart(partialStr.getArray(), partialStr.getStart(), partialStr.getEnd(), out);
}
public void writeStringEnd() {
out.write('"');
}
public void write(long number) {
JSONUtil.writeNumber(number, out);
}
public void write(double number) {
JSONUtil.writeNumber(number, out);
}
public void write(boolean bool) {
JSONUtil.writeBoolean(bool, out);
}
public void writeNumber(CharArr digits) {
out.write(digits);
}
public void writePartialNumber(CharArr digits) {
out.write(digits);
}
public void startObject() {
out.write('{');
level++;
}
public void endObject() {
out.write('}');
level--;
}
public void startArray() {
out.write('[');
level++;
}
public void endArray() {
out.write(']');
level--;
}
public void writeValueSeparator() {
out.write(',');
}
public void writeNameSeparator() {
out.write(':');
}
}
////////////////////////
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.noggit;
import junit.framework.TestCase;
import java.io.IOException;
import java.util.*;
/**
* @author yonik
* @version $Id$
*/
public class TestObjectBuilder extends TestCase {
public void test(String val, Object expected) throws IOException {
val = val.replace('\'', '"');
JSONParser p = TestJSONParser.getParser(val);
Object v = ObjectBuilder.getVal(p);
String s1 = JSONUtil.toJSON(v);
String s2 = JSONUtil.toJSON(expected);
assertEquals(s1, s2);
// not make sure that it round-trips correctly
JSONParser p2 = TestJSONParser.getParser(s1);
Object v2 = ObjectBuilder.getVal(p2);
String s3 = JSONUtil.toJSON(v2);
assertEquals(s1, s3);
}
public static List A(Object... lst) {
return Arrays.asList(lst);
}
public static Map O(Object... lst) {
LinkedHashMap map = new LinkedHashMap();
for (int i = 0; i < lst.length; i += 2) {
map.put(lst[i].toString(), lst[i + 1]);
}
return map;
}
public void testVariations(String str, Object expected) throws IOException {
test("[" + str + "]", A(expected));
test("[" + str + "," + str + "]", A(expected, expected));
test("{'foo':" + str + "}", O("foo", expected));
test("{'foo':" + str + ",'bar':{'a':" + str + "},'baz':[" + str + "]}",
O("foo", expected, "bar", O("a", expected), "baz", A(expected)));
}
public void testBuilder() throws IOException {
testVariations("[]", A());
testVariations("[]", A());
testVariations("{}", O());
testVariations("[[]]", A(A()));
testVariations("{'foo':{}}", O("foo", O()));
testVariations("[false,true,1,1.4,null,'hi']", A(false, true, 1, 1.4, null, "hi"));
}
}