1/* 2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * - Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 11 * - Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * - Neither the name of Oracle nor the names of its 16 * contributors may be used to endorse or promote products derived 17 * from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS 20 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 21 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 27 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32// Usage: jjs javacastcounter.js -- <.java files> 33 34// This example demonstrates Nashorn Java.extend API 35// to subclass a Java class from script. 36 37// This example uses Javac Compiler and Tree API 38// to list type casts used in java source files. 39 40if (arguments.length == 0) { 41 print("Usage: jjs javacastcounter.js -- <.java files>"); 42 exit(1); 43} 44 45// Java types used 46var ToolProvider = Java.type("javax.tools.ToolProvider"); 47var TreeScanner = Java.type("com.sun.source.util.TreeScanner"); 48var Trees = Java.type("com.sun.source.util.Trees"); 49var StringArray = Java.type("java.lang.String[]"); 50 51// get the system compiler tool 52var compiler = ToolProvider.systemJavaCompiler; 53 54// get standard file manager 55var fileMgr = compiler.getStandardFileManager(null, null, null); 56 57// make a list of compilation unit from command line argument file names 58// Using Java.to convert script array (arguments) to a Java String[] 59var compUnits = fileMgr.getJavaFileObjects(Java.to(arguments, StringArray)); 60 61// create a new compilation task 62var task = compiler.getTask(null, fileMgr, null, null, null, compUnits); 63 64// SourcePositions object to get positions of AST nodes 65var sourcePositions = Trees.instance(task).sourcePositions; 66 67// Subclass TreeScanner class 68var CastCounter = Java.extend(TreeScanner); 69 70var counter = new CastCounter() { 71 // current CompilationUnitTree 72 compUnit: null, 73 // current LineMap (pos -> line, column) 74 lineMap: null, 75 // current compilation unit's file name 76 fileName: null, 77 78 // overrides of TreeScanner methods 79 80 visitCompilationUnit: function(node, p) { 81 // capture info about current Compilation unit 82 this.compUnit = node; 83 this.lineMap = node.lineMap; 84 this.fileName = node.sourceFile.name; 85 86 // Using Java.super API to call super class method here 87 return Java.super(counter).visitCompilationUnit(node, p); 88 }, 89 90 visitTypeCast: function(node, p) { 91 // print information on this type cast node 92 var pos = sourcePositions.getStartPosition(this.compUnit, node); 93 var line = this.lineMap.getLineNumber(pos); 94 var col = this.lineMap.getColumnNumber(pos); 95 print(node + " @ " + this.fileName + ":" + line + ":" + col); 96 97 // count one more type cast 98 return 1; 99 }, 100 101 reduce: function(r1, r2) { 102 return (r1 == null ? 0 : r1) + (r2 == null ? 0 : r2); 103 } 104}; 105 106// print total number of type cast nodes seen 107print("Total casts:", counter.scan(task.parse(), null)); 108