package com.sun.tools.javac.processing;
import java.io.IOException;
import java.io.Writer;
import java.util.List;
import java.util.Set;
import java.util.Stack;
import javax.annotation.processing.AbstractProcessor;
import javax.annotation.processing.Filer;
import javax.annotation.processing.Messager;
import javax.annotation.processing.ProcessingEnvironment;
import javax.annotation.processing.RoundEnvironment;
import javax.annotation.processing.SupportedAnnotationTypes;
import javax.lang.model.element.Element;
import javax.lang.model.element.ElementKind;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.Modifier;
import javax.lang.model.element.NestingKind;
import javax.lang.model.element.PackageElement;
import javax.lang.model.element.TypeElement;
import javax.lang.model.element.TypeParameterElement;
import javax.lang.model.element.VariableElement;
import javax.lang.model.type.ArrayType;
import javax.lang.model.type.DeclaredType;
import javax.lang.model.type.TypeKind;
import javax.lang.model.type.TypeMirror;
import javax.lang.model.util.Elements;
import javax.lang.model.util.SimpleElementVisitor7;
import javax.lang.model.SourceVersion;
import javax.tools.JavaFileObject;
import douyu.http.HttpMethod;
import douyu.mvc.Action;
import douyu.mvc.Controller;
import douyu.mvc.Model;
/**
*
* @author ZHH
*
*/
//如果用这个，则在java1.6中会出错
//见com.sun.tools.javac.processing.JavacProcessingEnvironment.ProcessorState.checkSourceVersionCompatibility
//Override掉超类的getSupportedSourceVersion()更合适一些
//@SupportedSourceVersion(SourceVersion.RELEASE_7)
@SupportedAnnotationTypes("douyu.mvc.Controller")
//@SupportedAnnotationTypes("*")
public class ControllerProcessor extends AbstractProcessor {
private static String SUFFIX = "$DOUYU";
private static String CONTROLLER_VAR_NAME = "_c";
private static int varCount = 1;
@Override
public SourceVersion getSupportedSourceVersion() {
return SourceVersion.latest();
}
@Override
public boolean process(Set<? extends TypeElement> tes, RoundEnvironment renv) {
//JavacProcessingEnvironment处理到最后一个Round时，我们就不再管它了。
if (tes == null || tes.size() == 0)
return false;
//renv.getRootElements()返回的Element并不是都有@Controller的
//按理说用@SupportedAnnotationTypes指明我的Processor只处理哪些注解，javac就应该返回带有@Controller注解的Element，
//但是实际情况并不是这样，所以这里要再判断一下。
for (Element element : renv.getRootElements()) {
ElementKind kind = element.getKind();
if (kind != ElementKind.CLASS) //有可能是package-info.java中指定的PackageElement(也就是PackageSymbol)
continue;
//只处理最顶层的类
NestingKind nestingKind = ((TypeElement) element).getNestingKind();
if (nestingKind != NestingKind.TOP_LEVEL)
continue;
Controller controller = element.getAnnotation(Controller.class);
if (controller == null)
continue;
varCount = 1; //在开发阶段，如果不断更改源文件，会不断重新编译，这个值如果不清零，会一直加
String className = ((TypeElement) element).getQualifiedName().toString() + SUFFIX;
new ControllerElementVisitor(controller, processingEnv).visit(element).writeTo(className);
}
return true;
}
private static class ControllerElementVisitor extends SimpleElementVisitor7<ControllerElementVisitor, Void> {
private final ProcessingEnvironment processingEnv;
private final Elements elementUtils;
private final Messager messager;
private final Filer filer;
private final Controller controller;
private final PrettyPrinter p = new PrettyPrinter();
public ControllerElementVisitor(Controller controller, ProcessingEnvironment processingEnv) {
this.processingEnv = processingEnv;
this.elementUtils = processingEnv.getElementUtils();
this.messager = processingEnv.getMessager();
this.filer = processingEnv.getFiler();
this.controller = controller;
}
public void writeTo(String className) {
try {
JavaFileObject jfo = filer.createSourceFile(className, (Element[]) null);
Writer w = jfo.openWriter();
w.write(p.toString());
//在com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing中会调用filer.warnIfUnclosedFiles()
//所以必需要close，否则JavacProcessingEnvironment会出错
w.close();
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public ControllerElementVisitor visitType(TypeElement e, Void v) {
//带有@Controller的类必需是public的
if (!e.getModifiers().contains(Modifier.PUBLIC)) {
messager.printMessage(javax.tools.Diagnostic.Kind.ERROR, "class with @Controller must be 'public'", e);
return this;
}
List<? extends Element> enclosedElements = e.getEnclosedElements();
//带有@Controller的类必需有一个public的默认构造函数
boolean find = false;
for (Element element : enclosedElements) {
if (element.getKind() == ElementKind.CONSTRUCTOR && element.getModifiers().contains(Modifier.PUBLIC)
&& ((ExecutableElement) element).getParameters().size() == 0) {
find = true;
break;
}
}
if (!find) {
messager.printMessage(javax.tools.Diagnostic.Kind.ERROR,
"class with @Controller must contain a 'public' 0-parameter constructor", e);
return this;
}
PackageElement pkg = elementUtils.getPackageOf(e);
if (!pkg.isUnnamed()) {
p.println("package " + pkg.getQualifiedName() + ";");
p.println();
}
String simpleName = e.getSimpleName().toString();
p.print("public class ").append(simpleName).append(SUFFIX).append(" extends org.douyu.mvc.AbstractContext {");
p.println();
p.tab++;
p.print("private static ").append(simpleName).append(" ").append(CONTROLLER_VAR_NAME).append(" = new ").append(
simpleName).append("();");
p.println();
p.println();
p.println("protected void executeAction() throws Exception {");
p.tab++;
p.println("String p;");
p.print("if(actionName == null) actionName = \"").append(controller.defaultAction()).append("\";");
p.println();
p.println();
for (Element element : enclosedElements) {
if (element.getKind() == ElementKind.METHOD)
this.visit(element);
}
p.println("else {");
p.tab++;
p.println("response.sendError(404, request.getRequestURI());");
p.tab--;
p.println("}");
p.tab--;
p.println("}");
p.tab--;
p.println("}");
return this;
}
private boolean isFirstAction = true;
@Override
public ControllerElementVisitor visitExecutable(ExecutableElement e, Void v) {
ElementKind kind = e.getKind();
if (kind != ElementKind.METHOD)
return this;
Set<Modifier> modifiers = e.getModifiers();
if (!modifiers.contains(Modifier.PUBLIC) || modifiers.contains(Modifier.STATIC))
return this;
HttpMethod[] httpMethods = null;
Action action = e.getAnnotation(Action.class);
if (action != null) {
httpMethods = action.httpMethods();
}
if (httpMethods == null || httpMethods.length == 0) {
httpMethods = controller.httpMethods();
}
StringBuilder methods = new StringBuilder("checkHttpMethods(");
String sep = "";
if (httpMethods != null && httpMethods.length > 0) {
for (HttpMethod hm : httpMethods) {
methods.append(sep).append("\"").append(hm.name()).append("\"");
sep = ",";
}
}
methods.append(");");
if (isFirstAction) {
p.print("if(actionName.equals(\"").append(e.getSimpleName()).append("\")) {");
isFirstAction = false;
} else {
p.print("else if(actionName.equals(\"").append(e.getSimpleName()).append("\")) {");
}
p.println();
p.tab++;
p.println(methods);
printMethodParameters(p, CONTROLLER_VAR_NAME, e, processingEnv, null);
p.tab--;
p.println("}");
return this;
}
@Override
public ControllerElementVisitor visitVariable(VariableElement e, Void v) {
return this;
}
@Override
public ControllerElementVisitor visitTypeParameter(TypeParameterElement e, Void v) {
return this;
}
@Override
public ControllerElementVisitor visitPackage(PackageElement e, Void v) {
return this;
}
@Override
protected ControllerElementVisitor defaultAction(Element e, Void v) {
return this;
}
}
private static class ModelElementVisitor extends SimpleElementVisitor7<ModelElementVisitor, Void> {
private final ProcessingEnvironment processingEnv;
private final Messager messager;
private final PrettyPrinter p;
private final String prefixModelVarName;
private final String invokerModelVarName;
public ModelElementVisitor(PrettyPrinter p, String prefixModelVarName, String invokerModelVarName,
ProcessingEnvironment processingEnv) {
this.processingEnv = processingEnv;
this.messager = processingEnv.getMessager();
this.p = p;
this.prefixModelVarName = prefixModelVarName;
this.invokerModelVarName = invokerModelVarName;
}
@Override
public ModelElementVisitor visitType(TypeElement e, Void v) {
//带有@Model的类必需是public的
if (!e.getModifiers().contains(Modifier.PUBLIC)) {
messager.printMessage(javax.tools.Diagnostic.Kind.ERROR, "class with @Model must be 'public'", e);
return this;
}
List<? extends Element> enclosedElements = e.getEnclosedElements();
//带有@Model的类必需有一个public的默认构造函数
boolean find = false;
for (Element element : enclosedElements) {
if (element.getKind() == ElementKind.CONSTRUCTOR && element.getModifiers().contains(Modifier.PUBLIC)
&& ((ExecutableElement) element).getParameters().size() == 0) {
find = true;
break;
}
}
if (!find) {
messager.printMessage(javax.tools.Diagnostic.Kind.ERROR,
"class with @Model must contain a 'public' 0-parameter constructor", e);
return this;
}
String qualifiedName = e.getQualifiedName().toString();
p.print(qualifiedName).append(" ").append(invokerModelVarName).append(" = new ").append(qualifiedName).append("();");
p.println();
for (Element element : enclosedElements) {
if (element.getKind() == ElementKind.METHOD) {
ExecutableElement method = (ExecutableElement) element;
Set<Modifier> modifiers = method.getModifiers();
if (!modifiers.contains(Modifier.PUBLIC) || modifiers.contains(Modifier.STATIC))
continue;
if (method.getReturnType().getKind() != TypeKind.VOID)
continue;
if (method.getParameters().size() == 0)
continue;
if (!method.getSimpleName().toString().startsWith("set"))
continue;
printMethodParameters(p, invokerModelVarName, method, processingEnv, prefixModelVarName);
}
}
return this;
}
@Override
public ModelElementVisitor visitExecutable(ExecutableElement e, Void v) {
return this;
}
@Override
public ModelElementVisitor visitVariable(VariableElement e, Void v) {
return this;
}
@Override
public ModelElementVisitor visitTypeParameter(TypeParameterElement e, Void v) {
return this;
}
@Override
public ModelElementVisitor visitPackage(PackageElement e, Void v) {
return this;
}
@Override
protected ModelElementVisitor defaultAction(Element e, Void v) {
return this;
}
}
//TODO 是否考虑重构，做成ActionParameterType类那样吗?
//难点是下面每个if语句并没有统一规律，不好生成字符串。
private static void printMethodParameters(PrettyPrinter p, String invoker, ExecutableElement e,
ProcessingEnvironment processingEnv, String varPrefix) {
List<? extends VariableElement> vars = e.getParameters();
if (vars == null || vars.size() == 0) {
p.print(invoker).append(".").append(e.getSimpleName()).append("();");
p.println();
} else {
String sep = "";
StringBuilder s = new StringBuilder();
TypeMirror varType;
String type;
String name;
for (VariableElement var : vars) {
varType = var.asType();
type = varType.toString();
name = var.getSimpleName().toString();
if (varPrefix != null)
name = varPrefix + "." + name;
if ("douyu.mvc.Context".equals(type) || "douyu.mvc.ModelManager".equals(type)
|| "douyu.mvc.ViewManager".equals(type) || "douyu.mvc.ControllerManager".equals(type)) {
s.append(sep).append("this");
} else if ("javax.servlet.http.HttpServletRequest".equals(type) || "javax.servlet.ServletRequest".equals(type)) {
s.append(sep).append("request");
} else if ("javax.servlet.http.HttpServletResponse".equals(type) || "javax.servlet.ServletResponse".equals(type)) {
s.append(sep).append("response");
} else if ("javax.servlet.ServletContext".equals(type)) {
s.append(sep).append("servletContext");
} else if ("java.io.PrintWriter".equals(type) || "java.io.Writer".equals(type)) {
s.append(sep).append("response.getWriter()");
} else if ("java.lang.String".equals(type)) {
s.append(sep).append("request.getParameter(\"");
s.append(name).append("\")");
} else if ("int".equals(type)) {
p.print("int ").append("v").append(varCount).append(" = 0;");
p.println();
p.print("p = request.getParameter(\"").append(name).append("\");");
p.println();
p.print("if(p != null) v").append(varCount).append(" = Integer.parseInt(p);");
p.println();
p.println();
s.append(sep).append("v").append(varCount);
varCount++;
} else if ("long".equals(type)) {
p.print("long ").append("v").append(varCount).append(" = 0L;");
p.println();
p.print("p = request.getParameter(\"").append(name).append("\");");
p.println();
p.print("if(p != null) v").append(varCount).append(" = Long.parseLong(p);");
p.println();
p.println();
s.append(sep).append("v").append(varCount);
varCount++;
} else if ("float".equals(type)) {
p.print("float ").append("v").append(varCount).append(" = 0.0F;");
p.println();
p.print("p = request.getParameter(\"").append(name).append("\");");
p.println();
p.print("if(p != null) v").append(varCount).append(" = Float.parseFloat(p);");
p.println();
p.println();
s.append(sep).append("v").append(varCount);
varCount++;
} else if ("double".equals(type)) {
p.print("double ").append("v").append(varCount).append(" = 0.0D;");
p.println();
p.print("p = request.getParameter(\"").append(name).append("\");");
p.println();
p.print("if(p != null) v").append(varCount).append(" = Double.parseDouble(p);");
p.println();
p.println();
s.append(sep).append("v").append(varCount);
varCount++;
} else if ("boolean".equals(type)) {
p.print("boolean ").append("v").append(varCount).append(" = false;");
p.println();
p.print("p = request.getParameter(\"").append(name).append("\");");
p.println();
p.print("if(p != null) v").append(varCount).append(" = Boolean.parseBoolean(p);");
p.println();
p.println();
s.append(sep).append("v").append(varCount);
varCount++;
} else if ("byte".equals(type)) {
p.print("byte ").append("v").append(varCount).append(" = 0;");
p.println();
p.print("p = request.getParameter(\"").append(name).append("\");");
p.println();
p.print("if(p != null) v").append(varCount).append(" = Byte.parseByte(p);");
p.println();
p.println();
s.append(sep).append("v").append(varCount);
varCount++;
} else if ("short".equals(type)) {
p.print("short ").append("v").append(varCount).append(" = 0;");
p.println();
p.print("p = request.getParameter(\"").append(name).append("\");");
p.println();
p.print("if(p != null) v").append(varCount).append(" = Short.parseShort(p);");
p.println();
p.println();
s.append(sep).append("v").append(varCount);
varCount++;
} else if ("char".equals(type)) {
p.print("char ").append("v").append(varCount).append(" = 0;");
p.println();
p.print("p = request.getParameter(\"").append(name).append("\");");
p.println();
p.print("if(p != null && p.length() > 0) v").append(varCount).append(" = p.charAt(0);");
p.println();
p.println();
s.append(sep).append("v").append(varCount);
varCount++;
} else if ("java.lang.Integer".equals(type) || "java.lang.Long".equals(type) || "java.lang.Float".equals(type)
|| "java.lang.Double".equals(type) || "java.lang.Boolean".equals(type) || "java.lang.Byte".equals(type)
|| "java.lang.Short".equals(type)) {
type = type.substring(type.lastIndexOf('.') + 1);
p.print(type).append(" v").append(varCount).append(" = null;");
p.println();
p.print("p = request.getParameter(\"").append(name).append("\");");
p.println();
p.print("if(p != null) v").append(varCount).append(" = ").append(type).append(".valueOf(p);");
p.println();
p.println();
s.append(sep).append("v").append(varCount);
varCount++;
} else if ("java.lang.Character".equals(type)) {
p.print("Character v").append(varCount).append(" = null;");
p.println();
p.print("p = request.getParameter(\"").append(name).append("\");");
p.println();
p.print("if(p != null && p.length() > 0) v").append(varCount).append(" = p.charAt(0);");
p.println();
p.println();
s.append(sep).append("v").append(varCount);
varCount++;
} else if (varType.getKind() == TypeKind.ARRAY
&& "java.lang.String".equals(((ArrayType) varType).getComponentType().toString())) {
s.append(sep).append("request.getParameterValues(\"").append(name).append("\")");
} else if ("javax.servlet.http.Part".equals(type)) {
s.append(sep).append("request.getPart(\"").append(name).append("\")");
} else if (varType.getKind() == TypeKind.ARRAY
&& "javax.servlet.http.Part".equals(((ArrayType) varType).getComponentType().toString())) {
p.print("javax.servlet.http.Part[] ").append("v").append(varCount).append(" = null;");
p.println();
p.println("java.util.Collection<javax.servlet.http.Part> __parts = request.getParts();");
p.print("if(__parts != null) v").append(varCount).append(
" = __parts.toArray(new javax.servlet.http.Part[0]);");
p.println();
p.println();
s.append(sep).append("v").append(varCount);
varCount++;
} else {
//只注入带有@Model的类，其他的都注入null
if (varType.getKind() == TypeKind.DECLARED) {
Element element = ((DeclaredType) varType).asElement();
if (element.getAnnotation(Model.class) != null) {
String invokerModelVarName;
//防止循环setXXX
//如A.setXXX(B b), B.setYYY(A a)
//出现这种情况时，B直接用A的引用
int index = modelElementStack.indexOf(element);
if (index != -1) {
invokerModelVarName = modelVarNameStack.get(index);
} else {
invokerModelVarName = "v" + varCount;
varCount++;
modelElementStack.push(element);
modelVarNameStack.push(invokerModelVarName);
try {
new ModelElementVisitor(p, name, invokerModelVarName, processingEnv).visit(element);
} finally {
modelElementStack.pop();
modelVarNameStack.pop();
}
}
s.append(sep).append(invokerModelVarName);
} else {
s.append(sep).append("null");
}
//TODO 支持Model数组
//} else if (varType.getKind() == TypeKind.ARRAY
// && ((ArrayType) varType).getComponentType().getKind() == TypeKind.DECLARED) {
// Element element = ((DeclaredType) ((ArrayType) varType).getComponentType()).asElement();
} else {
s.append(sep).append("null");
}
}
sep = ",";
}
p.print(invoker).append(".").append(e.getSimpleName()).append("(").append(s).append(");");
p.println();
}
}
private static Stack<Element> modelElementStack = new Stack<Element>();
private static Stack<String> modelVarNameStack = new Stack<String>();
}