Java tutorial
/** * Copyright (C) 2015 BonitaSoft S.A. * BonitaSoft, 32 rue Gustave Eiffel - 38000 Grenoble * This library is free software; you can redistribute it and/or modify it under the terms * of the GNU Lesser General Public License as published by the Free Software Foundation * version 2.1 of the License. * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU Lesser General Public License for more details. * You should have received a copy of the GNU Lesser General Public License along with this * program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth * Floor, Boston, MA 02110-1301, USA. **/ package org.bonitasoft.engine.api.internal.servlet; import java.io.BufferedReader; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.PrintWriter; import java.util.ArrayList; import java.util.Arrays; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.apache.commons.fileupload.FileItemIterator; import org.apache.commons.fileupload.FileItemStream; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.servlet.ServletFileUpload; import org.apache.commons.io.IOUtils; import org.bonitasoft.engine.io.IOUtil; /** * @author Severin Moussel */ public abstract class ServletCall { private static final String BINARY_PARAMETER = "binaryParameter"; private String inputStream = null; /** * The parameters of the URL.<br /> * Result of the parsing of the query string : "?a=b&c=d&..." */ protected Map<String, String> parameters = null; /** * The request made to access this servletCall. */ private final HttpServletRequest request; /** * The response to return. */ private final HttpServletResponse response; private final List<byte[]> binaryParameters; /** * Default constructor. * * @param request * The request made to access this servletCall. * @param response * The response to return. * @throws IOException * @throws FileUploadException */ public ServletCall(final HttpServletRequest request, final HttpServletResponse response) throws FileUploadException, IOException { super(); this.request = request; this.response = response; parameters = new HashMap<String, String>(); binaryParameters = new ArrayList<byte[]>(); if (ServletFileUpload.isMultipartContent(request)) { final ServletFileUpload upload = new ServletFileUpload(); // Parse the request final FileItemIterator iter = upload.getItemIterator(request); while (iter.hasNext()) { try { final FileItemStream item = iter.next(); final InputStream stream = item.openStream(); String fieldName = item.getFieldName(); if (fieldName.startsWith(BINARY_PARAMETER)) { binaryParameters.add(IOUtil.getAllContentFrom(stream)); } else { String read = IOUtil.read(stream); parameters.put(fieldName, read); } stream.close(); } catch (final Exception t) { throw new IOException(t); } } } else { final Map<String, String[]> parameterMap = this.request.getParameterMap(); final Set<Entry<String, String[]>> entrySet = parameterMap.entrySet(); for (final Entry<String, String[]> entry : entrySet) { parameters.put(entry.getKey(), entry.getValue()[0]); } } } /** * @return the binaryParameters */ public List<byte[]> getBinaryParameters() { return binaryParameters; } public byte[] serialize(final Object obj) throws IOException { final ByteArrayOutputStream b = new ByteArrayOutputStream(); final ObjectOutputStream o = new ObjectOutputStream(b); o.writeObject(obj); return b.toByteArray(); } public Object deserialize(final byte[] bytes) throws IOException, ClassNotFoundException { final ByteArrayInputStream b = new ByteArrayInputStream(bytes); final ObjectInputStream o = new ObjectInputStream(b); return o.readObject(); } // ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// // PARAMETERS // ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// /** * Get the current call's HttpSession * * @return This method returns the session from the current call. */ public HttpSession getHttpSession() { return request.getSession(); } /** * @see javax.servlet.http.HttpServletRequest#getQueryString() */ public String getQueryString() { return request.getQueryString(); } /** * Reconstruct the URL the client used to make the request. * The returned URL contains a protocol, server name, port * number, and server path, but it does not include query * string parameters. * * @return This method returns the reconstructed URL */ public final String getRequestURL() { return request.getRequestURL().toString(); } /** * Read the input stream and set it in a String */ public final String getInputStream() { if (inputStream == null) { try { final BufferedReader reader = request.getReader(); final StringBuilder sb = new StringBuilder(); String line = reader.readLine(); while (line != null) { sb.append(line + "\n"); line = reader.readLine(); } reader.close(); inputStream = sb.toString(); } catch (final IOException e) { throw new RuntimeException("Can't read input Stream.", e); } } return inputStream; } /** * Count the number of parameters passed in the URL * * @return This method returns the number of parameters in the URL */ public final int countParameters() { return parameters.size(); } /** * Get a parameter values by its name * * @param name * The name of the parameter (case sensitive) * @return This method returns the values of a parameter as a list of String or null if the parameter isn't defined */ public final List<String> getParameterAsList(final String name) { return getParameterAsList(name, (String) null); } /** * Get a parameter values by its name * * @param name * The name of the parameter (case sensitive) * @param defaultValue * The value to return if the parameter isn't define * @return This method returns the values of a parameter as a list of String */ public final List<String> getParameterAsList(final String name, final String defaultValue) { if (parameters.containsKey(name)) { return Arrays.asList(parameters.get(name)); } if (defaultValue != null) { final List<String> results = new ArrayList<String>(); results.add(defaultValue); return results; } return null; } /** * Get a parameter first value by its name * * @param name * The name of the parameter (case sensitive) * @return This method returns the first value of a parameter as a String or null if the parameter isn't define */ public final String getParameter(final String name) { return getParameter(name, (String) null); } /** * Get a parameter first value by its name * * @param name * The name of the parameter (case sensitive) * @param defaultValue * The value to return if the parameter isn't define * @return This method returns the first value of a parameter as a String */ public final String getParameter(final String name, final String defaultValue) { if (parameters.containsKey(name)) { return parameters.get(name); } return defaultValue; } // ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// // GENERATE RESPONSES // ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// /** * Write into the output header. * * @param name * The name of the header to write. * @param value * The value of the header to write. */ protected final void head(final String name, final String value) { response.addHeader(name, value); } /** * Output a file * * @param file * The file to output */ protected final void output(final File file) { try { output(new FileInputStream(file)); } catch (final FileNotFoundException e) { error("Can not download file.", HttpServletResponse.SC_INTERNAL_SERVER_ERROR); } } /** * Output a stream as a file * * @param stream * The stream to output * @param filename * The name of the file to retrieve with the stream. */ protected void output(final InputStream stream, final String filename) { response.addHeader("Content-Disposition", "attachment; filename=" + filename + ";"); output(stream); } /** * Output a stream as a file * * @param stream * The stream to output */ protected void output(final InputStream stream) { response.setContentType("application/octet-stream"); try { IOUtils.copy(stream, response.getOutputStream()); } catch (final IOException e) { error("Can not download stream.", HttpServletResponse.SC_INTERNAL_SERVER_ERROR); } } protected void error(final String message, final int errorCode) { output(message); response.setStatus(errorCode); } /** * Write into the output * * @param string * The string to output */ protected final void output(final String string) { final PrintWriter outputWriter = getOutputWriter(); outputWriter.print(string); outputWriter.flush(); outputWriter.close(); } /** * Write into the output * * @param object * An object that will be transform into JSon */ protected final void output(final Object object) { final PrintWriter outputWriter = getOutputWriter(); // FIXME use xstream outputWriter.print(object.toString()); outputWriter.flush(); outputWriter.close(); } /** * The outputWriter in which to write the response String. */ private PrintWriter outputWriter = null; /** * Prepare the output * * @param response */ private PrintWriter getOutputWriter() { if (outputWriter == null) { response.setContentType("application/json;charset=UTF-8"); try { outputWriter = response.getWriter(); } catch (final IOException e) { throw new RuntimeException(e); } } return outputWriter; } // ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// // REQUEST ENTRY POINTS // ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// /** * Entry point for GET and SEARCH */ public abstract void doGet(); /** * Entry point for CREATE */ public abstract void doPost(); /** * Entry point for UPDATE */ public abstract void doPut(); /** * Entry point for DELETE */ public abstract void doDelete(); }