javaparser试用

浅浅的花香味﹌ 2022-06-13 09:55 331阅读 0赞

1、参考文档：[http://code.google.com/p/javaparser/wiki/UsingThisParser][http_code.google.com_p_javaparser_wiki_UsingThisParser]

2、添加maven依赖：

<repository>  
           <id>javaparser</id>  
           <name>JavaParser Repository</name>  
           <url>http://javaparser.googlecode.com/svn/maven2</url>  
           <snapshots>  
               <enabled>false</enabled>  
           </snapshots>  
       </repository>

<dependency>  
           <groupId>com.google.code.javaparser</groupId>  
           <artifactId>javaparser</artifactId>  
           <version>1.0.8</version>  
       </dependency>

download源代码：

svn checkouthttp://javaparser.googlecode.com/svn/trunk/ javaparser-read-only

3、常用API的使用

## Printing the CompilationUnit to System output ##

public class CuPrinter {
       
    
        public static void main(String[] args) throws Exception {
       
            // creates an input stream for the file to be parsed
            FileInputStream in = new FileInputStream("test.java");
    
            CompilationUnit cu;
            try {
       
                // parse the file
                cu = JavaParser.parse(in);
            } finally {
       
                in.close();
            }
    
            // prints the resulting compilation unit to default system output
            System.out.println(cu.toString());
        }

## Visiting class methods ##

public class MethodPrinter {
       
    
        public static void main(String[] args) throws Exception {
       
            // creates an input stream for the file to be parsed
            FileInputStream in = new FileInputStream("test.java");
    
            CompilationUnit cu;
            try {
       
                // parse the file
                cu = JavaParser.parse(in);
            } finally {
       
                in.close();
            }
    
            // visit and print the methods names
            new MethodVisitor().visit(cu, null);
        }
    
        /**
         * Simple visitor implementation for visiting MethodDeclaration nodes. 
         */
        private static class MethodVisitor extends VoidVisitorAdapter {
       
    
            @Override
            public void visit(MethodDeclaration n, Object arg) {
       
                // here you can access the attributes of the method.
                // this method will be called for all methods in this 
                // CompilationUnit, including inner class methods
                System.out.println(n.getName());
            }
        }
    }

## Changing methods from a class with a visitor ##

public class MethodChanger {
       
    
        public static void main(String[] args) throws Exception {
       
            // creates an input stream for the file to be parsed
            FileInputStream in = new FileInputStream("test.java");
    
            CompilationUnit cu;
            try {
       
                // parse the file
                cu = JavaParser.parse(in);
            } finally {
       
                in.close();
            }
    
            // visit and change the methods names and parameters
            new MethodChangerVisitor().visit(cu, null);
    
            // prints the changed compilation unit
            System.out.println(cu.toString());
        }
    
        /**
         * Simple visitor implementation for visiting MethodDeclaration nodes.
         */
        private static class MethodChangerVisitor extends VoidVisitorAdapter {
       
    
            @Override
            public void visit(MethodDeclaration n, Object arg) {
       
                // change the name of the method to upper case
                n.setName(n.getName().toUpperCase());
    
                // create the new parameter
                Parameter newArg = ASTHelper.createParameter(ASTHelper.INT_TYPE, "value");
    
                // add the parameter to the method
                ASTHelper.addParameter(n, newArg);
            }
    
        }
    }

## Changing methods from a class without a visitor ##

public class MethodChanger {
       
    
        public static void main(String[] args) throws Exception {
       
            // creates an input stream for the file to be parsed
            FileInputStream in = new FileInputStream("test.java");
    
            CompilationUnit cu;
            try {
       
                // parse the file
                cu = JavaParser.parse(in);
            } finally {
       
                in.close();
            }
    
            // change the methods names and parameters
            changeMethods(cu);
    
            // prints the changed compilation unit
            System.out.println(cu.toString());
        }
    
        private static void changeMethods(CompilationUnit cu) {
       
            List<TypeDeclaration> types = cu.getTypes();
            for (TypeDeclaration type : types) {
       
                List<BodyDeclaration> members = type.getMembers();
                for (BodyDeclaration member : members) {
       
                    if (member instanceof MethodDeclaration) {
       
                        MethodDeclaration method = (MethodDeclaration) member;
                        changeMethod(method);
                    }
                }
            }
        }
    
        private static void changeMethod(MethodDeclaration n) {
       
            // change the name of the method to upper case
            n.setName(n.getName().toUpperCase());
    
            // create the new parameter
            Parameter newArg = ASTHelper.createParameter(ASTHelper.INT_TYPE, "value");
    
            // add the parameter to the method
            ASTHelper.addParameter(n, newArg);
        }
    }

## Creating a CompilationUnit from scratch ##

public class ClassCreator {
       
    
        public static void main(String[] args) throws Exception {
       
            // creates the compilation unit
            CompilationUnit cu = createCU();
    
            // prints the created compilation unit
            System.out.println(cu.toString());
        }
    
        /**
         * creates the compilation unit
         */
        private static CompilationUnit createCU() {
       
            CompilationUnit cu = new CompilationUnit();
            // set the package
            cu.setPakage(new PackageDeclaration(ASTHelper.createNameExpr("java.parser.test")));
    
            // create the type declaration 
            ClassOrInterfaceDeclaration type = new ClassOrInterfaceDeclaration(ModifierSet.PUBLIC, false, "GeneratedClass");
            ASTHelper.addTypeDeclaration(cu, type);
    
            // create a method
            MethodDeclaration method = new MethodDeclaration(ModifierSet.PUBLIC, ASTHelper.VOID_TYPE, "main");
            method.setModifiers(ModifierSet.addModifier(method.getModifiers(), ModifierSet.STATIC));
            ASTHelper.addMember(type, method);
    
            // add a parameter to the method
            Parameter param = ASTHelper.createParameter(ASTHelper.createReferenceType("String", 0), "args");
            param.setVarArgs(true);
            ASTHelper.addParameter(method, param);
    
            // add a body to the method
            BlockStmt block = new BlockStmt();
            method.setBody(block);
    
            // add a statement do the method body
            NameExpr clazz = new NameExpr("System");
            FieldAccessExpr field = new FieldAccessExpr(clazz, "out");
            MethodCallExpr call = new MethodCallExpr(field, "println");
            ASTHelper.addArgument(call, new StringLiteralExpr("Hello World!"));
            ASTHelper.addStmt(block, call);
    
            return cu;
        }
    }

4、结论：操作相比jdt更加的容易

http://tianya23.blog.51cto.com/1081650/617244

[http_code.google.com_p_javaparser_wiki_UsingThisParser]: http://code.google.com/p/javaparser/wiki/UsingThisParser