1、参考文档：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 checkout http://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
