|
1
21 package com.jaspersoft.jasperserver.war.common;
22
23 import java.io.BufferedOutputStream  ;
24 import java.io.ByteArrayOutputStream ;
25 import java.io.File ;
26 import java.io.FileInputStream ;
27 import java.io.FileNotFoundException ;
28 import java.io.FileOutputStream ;
29 import java.io.IOException ;
30 import java.io.OutputStream ;
31
32 import org.apache.commons.logging.Log;
33 import org.apache.commons.logging.LogFactory;
34
35 import com.jaspersoft.jasperserver.api.JSException;
36
37
41 public class FileBufferedOutputStream extends OutputStream {
42
43 private static final Log log = LogFactory.getLog(FileBufferedOutputStream.class);
44
45 public static final int DEFAULT_MEMORY_THRESHOLD = 1 << 18;
46 public static final int INFINIT_MEMORY_THRESHOLD = -1;
47 public static final int DEFAULT_INITIAL_MEMORY_BUFFER_SIZE = 1 << 16;
48 public static final int DEFAULT_INPUT_BUFFER_LENGTH = 1 << 14;
49
50 private final int memoryThreshold;
51 private final int initialMemoryBufferSize;
52 private final int inputBufferLenght;
53
54 private final ByteArrayOutputStream memoryOutput;
55 private int size;
56 private File file;
57 private BufferedOutputStream fileOutput;
58 private boolean closed;
59 private boolean disposed;
60
61 public FileBufferedOutputStream() {
62 this(DEFAULT_MEMORY_THRESHOLD, DEFAULT_INITIAL_MEMORY_BUFFER_SIZE, DEFAULT_INPUT_BUFFER_LENGTH);
63 }
64
65 public FileBufferedOutputStream(int memoryThreshold) {
66 this(memoryThreshold, DEFAULT_INITIAL_MEMORY_BUFFER_SIZE, DEFAULT_INPUT_BUFFER_LENGTH);
67 }
68
69 public FileBufferedOutputStream(int memoryThreshold, int initialMemoryBufferSize) {
70 this(memoryThreshold, initialMemoryBufferSize, DEFAULT_INPUT_BUFFER_LENGTH);
71 }
72
73 public FileBufferedOutputStream(int memoryThreshold, int initialMemoryBufferSize, int inputBufferLenght) {
74 this.memoryThreshold = memoryThreshold;
75 this.initialMemoryBufferSize = initialMemoryBufferSize;
76 this.inputBufferLenght = inputBufferLenght;
77
78 size = 0;
79 memoryOutput = this.memoryThreshold != 0 ? new ByteArrayOutputStream (this.initialMemoryBufferSize) : null;
80 }
81
82 public void write(int b) throws IOException {
83 checkClosed();
84
85 if (availableMemorySpace() > 0) {
86 memoryOutput.write(b);
87 } else {
88 ensureFileOutput().write(b);
89 }
90
91 ++size;
92 }
93
94 protected int availableMemorySpace() {
95 int availableMemorySpace;
96 if (memoryOutput != null
97 && (memoryThreshold < 0 || memoryOutput.size() < memoryThreshold)) {
98 availableMemorySpace = memoryThreshold - memoryOutput.size();
99 } else {
100 availableMemorySpace = 0;
101 }
102 return availableMemorySpace;
103 }
104
105 protected BufferedOutputStream ensureFileOutput() throws IOException , FileNotFoundException {
106 if (fileOutput == null) {
107 file = File.createTempFile("exported_report", ".tmp");
108 FileOutputStream fileOutputStream = new FileOutputStream (file);
109 fileOutput = new BufferedOutputStream (fileOutputStream);
110 }
111 return fileOutput;
112 }
113
114 public void write(byte[] b, int off, int len) throws IOException {
115 checkClosed();
116
117 int memoryLen = availableMemorySpace();
118 if (len < memoryLen) {
119 memoryLen = len;
120 }
121
122 if (memoryLen > 0) {
123 memoryOutput.write(b, off, memoryLen);
124 }
125
126 if (memoryLen < len) {
127 ensureFileOutput().write(b, off + memoryLen, len - memoryLen);
128 }
129
130 size += len;
131 }
132
133 public void checkClosed() {
134 if (closed) {
135 throw new JSException("Output stream already closed");
136 }
137 }
138
139 public void close() throws IOException {
140 if (!closed && fileOutput != null) {
141 fileOutput.flush();
142 fileOutput.close();
143 }
144
145 closed = true;
146 }
147
148 public void flush() throws IOException {
149 if (fileOutput != null) {
150 fileOutput.flush();
151 }
152 }
153
154 public int size() {
155 return size;
156 }
157
158 public void writeData(OutputStream out) throws IOException {
159 if (!closed) {
160 close();
161 }
162
163 if (memoryOutput != null) {
164 memoryOutput.writeTo(out);
165 }
166
167 if (file != null) {
168 FileInputStream fileInput = new FileInputStream (file);
169 boolean inputClosed = false;
170 try {
171 byte[] buffer = new byte[inputBufferLenght];
172 int read;
173 while((read = fileInput.read(buffer)) > 0) {
174 out.write(buffer, 0, read);
175 }
176 fileInput.close();
177 inputClosed = true;
178 } finally {
179 if (!inputClosed) {
180 try {
181 fileInput.close();
182 } catch (IOException e) {
183 log.warn("Could not close file input stream", e);
184 }
185 }
186 }
187 }
188 }
189
190 public void dispose() {
191 if (disposed) {
192 return;
193 }
194
195 boolean success = true;
196 if (!closed && fileOutput != null) {
197 try {
198 fileOutput.close();
199 } catch (IOException e) {
200 log.warn("Error while closing the temporary file output stream", e);
201 success = false;
202 }
203 }
204
205 if (file != null && !file.delete()) {
206 log.warn("Error while deleting the temporary file");
207 success = false;
208 }
209
210 disposed = success;
211 }
212
213 protected void finalize() throws Throwable {
214 dispose();
215 super.finalize();
216 }
217
218
219 }
220 |
Popular Tags |
Java API By Example, From Geeks To Geeks.