ARouter使用自定义注解处理器，自动生成跳转Activity的代码，避免手动填写和管理path

package com.agilezhu.processor; import com.alibaba.android.arouter.facade.annotation.Route; import com.google.auto.service.AutoService; import com.squareup.javapoet.ClassName; import com.squareup.javapoet.CodeBlock; import com.squareup.javapoet.JavaFile; import com.squareup.javapoet.MethodSpec; import com.squareup.javapoet.TypeSpec; import java.util.LinkedHashSet; import java.util.Set; import javax.annotation.processing.AbstractProcessor; import javax.annotation.processing.Filer; import javax.annotation.processing.Messager; import javax.annotation.processing.ProcessingEnvironment; import javax.annotation.processing.Processor; import javax.annotation.processing.RoundEnvironment; import javax.lang.model.SourceVersion; import javax.lang.model.element.Element; import javax.lang.model.element.Modifier; import javax.lang.model.element.TypeElement; import javax.lang.model.util.Elements; import javax.tools.Diagnostic; /** * Generate ARouterPage.java for ARouter */ @AutoService(Processor.class) public class ARouterProcessor extends AbstractProcessor { private Filer mFiler; //文件相关工具类：用于保存生成的java类文件 private Elements mElementUtils; //元素相关工具类：用于获取java类文件 private Messager mMessager;//用于打印日志 @Override public synchronized void init(ProcessingEnvironment processingEnvironment) { super.init(processingEnvironment); mFiler = processingEnv.getFiler(); mElementUtils = processingEnv.getElementUtils(); mMessager = processingEnv.getMessager(); } @Override public Set<String> getSupportedAnnotationTypes() { //返回该注解处理器能够处理哪些注解 Set<String> types = new LinkedHashSet<>(); types.add(Route.class.getName()); return types; } @Override public SourceVersion getSupportedSourceVersion() { //返回当前注解处理器支持的java版本号 return SourceVersion.latest(); } @Override public boolean process(Set<? extends TypeElement> set, RoundEnvironment roundEnvironment) { if (set == null || set.size() == 0) { return false; } //将要生成的java完整类名 String targetClassName = "ARouterPage"; String packageName = "com.agilezhu.processor.generate"; //创建方法(构造方法) MethodSpec.Builder bindMethodBuilder = MethodSpec.methodBuilder("<init>") .addModifiers(Modifier.PUBLIC); //创建类 TypeSpec.Builder aRouterPageClassBuilder = TypeSpec.classBuilder(targetClassName) .addModifiers(Modifier.PUBLIC, Modifier.FINAL); //获取所有的源码文件 Set<? extends Element> elements = roundEnvironment.getRootElements(); for (Element element : elements) { if (!(element instanceof TypeElement)) {//判断是否class类 continue; } //转换成class类型 TypeElement typeElement = (TypeElement) element; //当前文件的类名 String classSimpleName = element.getSimpleName().toString(); Route routeAnnotation = element.getAnnotation(Route.class); if (routeAnnotation == null) { continue; } mMessager.printMessage(Diagnostic.Kind.WARNING, "myProcess=====>>>>>" + classSimpleName); ClassName innerClassName = ClassName.get(packageName, targetClassName, classSimpleName); try { aRouterPageClassBuilder.addField(innerClassName, classSimpleName) .addType(TypeSpec.classBuilder(innerClassName.simpleName()) .addModifiers(Modifier.STATIC, Modifier.PUBLIC) .addField(String.class, "path", Modifier.PUBLIC, Modifier.STATIC) .addStaticBlock(CodeBlock.builder().addStatement("path= \"" + routeAnnotation.path() + "\"").build()) .addMethod(MethodSpec .methodBuilder("navigation") .addParameter(String.class,"key") .addParameter(ClassName.get("android.os","Bundle"), "params") .addStatement("com.alibaba.android.arouter.launcher.ARouter.getInstance().build(path).withBundle(key,params).navigation()") .addModifiers(Modifier.PUBLIC, Modifier.STATIC) .build()) .addMethod(MethodSpec .methodBuilder("navigation") .addStatement("com.alibaba.android.arouter.launcher.ARouter.getInstance().build(path).navigation()") .addModifiers(Modifier.PUBLIC, Modifier.STATIC) .build()) .build()); } catch (Exception e) { e.printStackTrace(); } //构造方法中添加初始化代码 bindMethodBuilder.addStatement(classSimpleName + ".path = \"" + routeAnnotation.path() + "\""); } aRouterPageClassBuilder.addMethod(bindMethodBuilder.build()); //创建java文件 JavaFile bindProxyFile = JavaFile .builder(packageName, aRouterPageClassBuilder.build()) .build(); try { //保存java类文件 bindProxyFile.writeTo(mFiler); } catch (Throwable e) { e.printStackTrace(); } return false; } }