|
1
55 package org.apache.avalon.framework;
56
57 import java.io.PrintWriter  ;
58 import java.io.StringWriter ;
59 import java.lang.reflect.Method ;
60 import java.util.StringTokenizer ;
61
62
70 public final class ExceptionUtil
71 {
72 private static final String LINE_SEPARATOR = System.getProperty( "line.separator" );
73 private static final String GET_CAUSE_NAME = "getCause";
74 private static final Class [] GET_CAUSE_PARAMTYPES = new Class [ 0 ];
75
76
79 private ExceptionUtil()
80 {
81 }
82
83
89 public static String printStackTrace( final Throwable throwable )
90 {
91 return printStackTrace( throwable, 0, true );
92 }
93
94
101 public static String printStackTrace( final Throwable throwable,
102 final boolean printCascading )
103 {
104 return printStackTrace( throwable, 0, printCascading );
105 }
106
107
116 public static String printStackTrace( final Throwable throwable, final int depth )
117 {
118 int dp = depth;
119 final String [] lines = captureStackTrace( throwable );
120
121 if( 0 == dp || dp > lines.length )
122 {
123 dp = lines.length;
124 }
125
126 final StringBuffer sb = new StringBuffer ();
127
128 for( int i = 0; i < dp; i++ )
129 {
130 sb.append( lines[ i ] );
131 sb.append( LINE_SEPARATOR );
132 }
133
134 return sb.toString();
135 }
136
137
145 public static String printStackTrace( final Throwable throwable,
146 final int depth,
147 final boolean printCascading )
148 {
149 return printStackTrace( throwable, depth, printCascading, true );
150 }
151
152
165 public static String printStackTrace( final Throwable throwable,
166 final int depth,
167 final boolean printCascading,
168 final boolean useReflection )
169 {
170 final String result = printStackTrace( throwable, depth );
171
172 if( !printCascading )
173 {
174 return result;
175 }
176 else
177 {
178 final StringBuffer sb = new StringBuffer ();
179 sb.append( result );
180
181 Throwable cause = getCause( throwable, useReflection );
182
183 while( null != cause )
184 {
185 sb.append( "rethrown from" );
186 sb.append( LINE_SEPARATOR );
187 sb.append( printStackTrace( cause, depth ) );
188
189 cause = getCause( cause, useReflection );
190 }
191
192 return sb.toString();
193 }
194 }
195
196
203 public static Throwable getCause( final Throwable throwable,
204 final boolean useReflection )
205 {
206 if( throwable instanceof CascadingThrowable )
207 {
208 return ( (CascadingThrowable)throwable ).getCause();
209 }
210 else if( useReflection )
211 {
212 try
213 {
214 final Class clazz = throwable.getClass();
215 final Method method =
216 clazz.getMethod( GET_CAUSE_NAME, GET_CAUSE_PARAMTYPES );
217 return (Throwable )method.invoke( throwable, null );
218 }
219 catch( final Throwable t )
220 {
221 return null;
222 }
223 }
224 else
225 {
226 return null;
227 }
228 }
229
230
236 public static String [] captureStackTrace( final Throwable throwable )
237 {
238 final StringWriter sw = new StringWriter ();
239 throwable.printStackTrace( new PrintWriter ( sw, true ) );
240 return splitStringInternal( sw.toString(), LINE_SEPARATOR );
241 }
242
243
251 public static String [] splitString( final String string, final String onToken )
252 {
253 return splitStringInternal( string, onToken );
254 }
255
256
263 private static String [] splitStringInternal( final String string, final String onToken )
264 {
265 final StringTokenizer tokenizer = new StringTokenizer ( string, onToken );
266 final String [] result = new String [ tokenizer.countTokens() ];
267
268 for( int i = 0; i < result.length; i++ )
269 {
270 result[ i ] = tokenizer.nextToken();
271 }
272
273 return result;
274 }
275 }
276 |
Popular Tags |
Java API By Example, From Geeks To Geeks.