diff options
Diffstat (limited to 'dx/src/com/android/dx/util/ExceptionWithContext.java')
-rw-r--r-- | dx/src/com/android/dx/util/ExceptionWithContext.java | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/dx/src/com/android/dx/util/ExceptionWithContext.java b/dx/src/com/android/dx/util/ExceptionWithContext.java new file mode 100644 index 0000000..7f8523c --- /dev/null +++ b/dx/src/com/android/dx/util/ExceptionWithContext.java @@ -0,0 +1,149 @@ +/* + * Copyright (C) 2007 The Android Open Source Project + * + * 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.android.dx.util; + +import java.io.PrintStream; +import java.io.PrintWriter; + +/** + * Exception which carries around structured context. + */ +public class ExceptionWithContext + extends RuntimeException { + /** {@code non-null;} human-oriented context of the exception */ + private StringBuffer context; + + /** + * Augments the given exception with the given context, and return the + * result. The result is either the given exception if it was an + * {@link ExceptionWithContext}, or a newly-constructed exception if it + * was not. + * + * @param ex {@code non-null;} the exception to augment + * @param str {@code non-null;} context to add + * @return {@code non-null;} an appropriate instance + */ + public static ExceptionWithContext withContext(Throwable ex, String str) { + ExceptionWithContext ewc; + + if (ex instanceof ExceptionWithContext) { + ewc = (ExceptionWithContext) ex; + } else { + ewc = new ExceptionWithContext(ex); + } + + ewc.addContext(str); + return ewc; + } + + /** + * Constructs an instance. + * + * @param message human-oriented message + */ + public ExceptionWithContext(String message) { + this(message, null); + } + + /** + * Constructs an instance. + * + * @param cause {@code null-ok;} exception that caused this one + */ + public ExceptionWithContext(Throwable cause) { + this(null, cause); + } + + /** + * Constructs an instance. + * + * @param message human-oriented message + * @param cause {@code null-ok;} exception that caused this one + */ + public ExceptionWithContext(String message, Throwable cause) { + super((message != null) ? message : + (cause != null) ? cause.getMessage() : null, + cause); + + if (cause instanceof ExceptionWithContext) { + String ctx = ((ExceptionWithContext) cause).context.toString(); + context = new StringBuffer(ctx.length() + 200); + context.append(ctx); + } else { + context = new StringBuffer(200); + } + } + + /** {@inheritDoc} */ + @Override + public void printStackTrace(PrintStream out) { + super.printStackTrace(out); + out.println(context); + } + + /** {@inheritDoc} */ + @Override + public void printStackTrace(PrintWriter out) { + super.printStackTrace(out); + out.println(context); + } + + /** + * Adds a line of context to this instance. + * + * @param str {@code non-null;} new context + */ + public void addContext(String str) { + if (str == null) { + throw new NullPointerException("str == null"); + } + + context.append(str); + if (!str.endsWith("\n")) { + context.append('\n'); + } + } + + /** + * Gets the context. + * + * @return {@code non-null;} the context + */ + public String getContext() { + return context.toString(); + } + + /** + * Prints the message and context. + * + * @param out {@code non-null;} where to print to + */ + public void printContext(PrintStream out) { + out.println(getMessage()); + out.print(context); + } + + /** + * Prints the message and context. + * + * @param out {@code non-null;} where to print to + */ + public void printContext(PrintWriter out) { + out.println(getMessage()); + out.print(context); + } +} |