com.google.orkut.client.api.Util.java Source code

Introduction

Here is the source code for com.google.orkut.client.api.Util.java

Source

/* EXPERIMENTAL (really) */
/* Copyright (c) 2009 Google Inc.
 *
 * Licensed 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 com.google.orkut.client.api;

import org.json.me.JSONArray;
import org.json.me.JSONException;
import org.json.me.JSONObject;

import java.util.Calendar;
import java.util.TimeZone;
import java.util.Vector;

/**
 * Contains utility functions required by the orkut client library
 *
 * @author Hari S
 */
public class Util {
    private Util() {
    }

    public static String getHttpVersionHeaderName() {
        return InternalConstants.ORKUT_CLIENT_LIB_HEADER;
    }

    public static String getHttpVersionHeaderValue() {
        return InternalConstants.VERSION_STRING;
    }

    public static boolean isEmpty(String str) {
        return null == str || "".equals(str);
    }

    public static boolean isEmptyOrWhiteSpace(String str) {
        return null == str || 0 == str.trim().length();
    }

    static String getRuntimeErrorMessage(String methodName) {
        return methodName + " : Unexpected exception ";
    }

    static void putJsonValue(JSONObject json, String key, Object value) {
        try {
            json.put(key, value);
        } catch (JSONException e) {
            throw new RuntimeException("Null key while writing into json", e);
        }
    }

    static String getFormattedTimestamp(long timeMillis) {
        Calendar cal = Calendar.getInstance(TimeZone.getTimeZone(Constants.DateFormatter.UTC));
        cal.setTimeInMillis(timeMillis);
        StringBuilder date = new StringBuilder();
        date.append(cal.get(Calendar.YEAR));
        date.append(Constants.DateFormatter.DATE_SEPARATOR);
        date.append(padSingleDigitNum(cal.get(Calendar.MONTH) + 1));
        date.append(Constants.DateFormatter.DATE_SEPARATOR);
        date.append(padSingleDigitNum(cal.get(Calendar.DATE)));
        date.append(Constants.DateFormatter.DATE_DELIM);
        date.append(padSingleDigitNum(cal.get(Calendar.HOUR)));
        date.append(Constants.DateFormatter.TIME_SEPARATOR);
        date.append(padSingleDigitNum(cal.get(Calendar.MINUTE)));
        date.append(Constants.DateFormatter.TIME_SEPARATOR);
        date.append(padSingleDigitNum(cal.get(Calendar.SECOND)));
        date.append(Constants.DateFormatter.TIME_DELIM);
        return date.toString();
    }

    static private String padSingleDigitNum(int num) {
        return (num < 10) ? ("0" + num) : ("" + num);
    }

    static Vector forEachItemInList(JSONObject data, String key, Converter processor) {
        Vector items = new Vector();
        try {
            JSONArray itemList = data.getJSONArray(key);
            if (itemList == null) {
                return items;
            }
            int numItems = itemList.length();
            for (int i = 0; i < numItems; i++) {
                JSONObject json = itemList.getJSONObject(i);
                try {
                    items.add(processor.convert(json));
                } catch (CreationException e) {
                    // ignore and skip conversion of this item
                } catch (RuntimeException e) {
                    // we skip any runtime exception too. This is to catch any exception
                    // that occurs while the object is being initialized.
                    // TODO(Sachin Shenoy): Don't silently eat up exception, provide
                    // mechanism to log these. 
                }
            }
        } catch (JSONException jse) {
            throw new RuntimeException("Unexpected json exception.", jse);
        }
        return items;
    }

    private static byte[] resizeVec(byte[] b, int newSize) {
        byte[] c = new byte[newSize];
        System.arraycopy(b, 0, c, 0, b.length > newSize ? newSize : b.length);
        return c;
    }

    /** Reads an input stream til EOF and returns all bytes read.
     *  The stream will NOT be closed.
     *
     *  @param is The input stream to read.
     *  @return An array of bytes that represents all bytes read
     *  from the stream until the end-of-file is reached.
     */
    public static byte[] readAllFrom(java.io.InputStream is) throws java.io.IOException {
        byte[] buf = new byte[8192];
        int i = 0;
        int n = 0, r;
        final int SIZE = 4096;

        while (true) {
            // invariant: buf[0..n-1] has the valid data
            // and buffer capacity is >= n

            // make sure buffer has capacity at least n + SIZE
            while (buf.length <= n + SIZE + 1)
                buf = resizeVec(buf, 2 * buf.length);

            // read into buf
            r = is.read(buf, n, SIZE);
            if (r <= 0)
                break; // end of stream

            n += r;
        }

        // resize the byte array to its correct size
        return resizeVec(buf, n);
    }

    /** Load a file and returns its content as a byte array.
     *
     *  @param fileName the name of the file to load.
     *  @return The full contents of the file as a byte array. */
    public static byte[] loadFile(String fileName) throws java.io.IOException {
        java.io.FileInputStream fin = new java.io.FileInputStream(fileName);
        byte[] b = readAllFrom(fin);
        fin.close();
        return b;
    }

    static class JSONUtil {

        static String getRequiredStringField(String fieldName, JSONObject dataObject) {
            try {
                return dataObject.getString(fieldName);
            } catch (JSONException jse) {
                throw new RequiredFieldNotFoundException(fieldName, dataObject);
            }
        }

        static int getRequiredIntField(String fieldName, JSONObject dataObject) {
            try {
                return dataObject.getInt(fieldName);
            } catch (JSONException jse) {
                throw new RequiredFieldNotFoundException(fieldName, dataObject);
            }
        }

        static JSONObject getRequiredJSONObjectField(String fieldName, JSONObject dataObject) {
            try {
                return dataObject.getJSONObject(fieldName);
            } catch (JSONException jse) {
                throw new RequiredFieldNotFoundException(fieldName, dataObject);
            }
        }
    }
}