1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.ant; 18 19 import org.apache.tools.ant.BuildException; 20 import org.apache.tools.ant.Task; 21 import org.apache.tools.ant.types.Path; 22 23 import java.io.File; 24 25 /** 26 * Single input single output class. Execution is controlled 27 * by modification timestamp of the input and output files. 28 * 29 * Implementation classes must implement {@link #createOutput()} 30 * 31 */ 32 public abstract class SingleInputOutputTask extends Task { 33 34 private String mInput; 35 private String mOutput; 36 setInput(Path inputPath)37 public void setInput(Path inputPath) { 38 mInput = TaskHelper.checkSinglePath("input", inputPath); 39 } 40 setOutput(Path outputPath)41 public void setOutput(Path outputPath) { 42 mOutput = TaskHelper.checkSinglePath("output", outputPath); 43 } 44 45 @Override execute()46 public final void execute() throws BuildException { 47 if (mInput == null) { 48 throw new BuildException("Missing attribute input"); 49 } 50 if (mOutput == null) { 51 throw new BuildException("Missing attribute output"); 52 } 53 54 // check if there's a need for the task to run. 55 File outputFile = new File(mOutput); 56 if (outputFile.isFile()) { 57 File inputFile = new File(mInput); 58 if (outputFile.lastModified() >= inputFile.lastModified()) { 59 System.out.println(String.format( 60 "Run cancelled: no changes to input file %1$s", 61 inputFile.getAbsolutePath())); 62 return; 63 } 64 } 65 66 createOutput(); 67 } 68 createOutput()69 protected abstract void createOutput() throws BuildException; 70 getInput()71 protected String getInput() { 72 return mInput; 73 } 74 getOutput()75 protected String getOutput() { 76 return mOutput; 77 } 78 } 79