com.ideaaedi.component.compile.DynamicJavaFileManager Maven / Gradle / Ivy
package com.ideaaedi.component.compile;
import javax.tools.FileObject;
import javax.tools.ForwardingJavaFileManager;
import javax.tools.JavaFileManager;
import javax.tools.JavaFileObject;
import javax.tools.StandardLocation;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
/**
* 自定义{@link JavaFileManager}文件管理器，用于管.java文件、.class文件
*
* 为什么要重写{@link JavaFileManager}？
*
*
* @author JustryDeng
* @since 2021/9/20 16:44:07
*/
public class DynamicJavaFileManager extends ForwardingJavaFileManager {
private final Map javaFileObjectMap = new ConcurrentHashMap<>(16);
private final DynamicClassLoader classLoader;
public DynamicJavaFileManager(JavaFileManager fileManager, DynamicClassLoader classLoader) {
super(fileManager);
this.classLoader = classLoader;
}
@Override
public FileObject getFileForInput(Location location, String packageName, String relativeName) throws IOException {
JavaFileObject javaFileObject = javaFileObjectMap.get(determineKey(location, packageName, relativeName));
if (javaFileObject != null) {
return javaFileObject;
}
return super.getFileForInput(location, packageName, relativeName);
}
/**
* 这里是编译器返回的同(源)Java文件对象,替换为CharSequenceJavaFileObject实现
*/
@Override
public JavaFileObject getJavaFileForOutput(Location location, String classLongName, JavaFileObject.Kind kind, FileObject sibling) throws IOException {
CharSequenceJavaFileObject javaFileObject = new CharSequenceJavaFileObject(classLongName, (InputStream) null);
classLoader.registerCompiledSource(classLongName, javaFileObject);
return javaFileObject;
}
@Override
public ClassLoader getClassLoader(Location location) {
// 使用自定义的类加载器
return classLoader;
}
@Override
public String inferBinaryName(Location location, JavaFileObject file) {
if (file instanceof CharSequenceJavaFileObject) {
return file.getName();
}
return super.inferBinaryName(location, file);
}
/**
* 寻找JavaFileObject
*
* 注：这个方法很关键，一个.java文件，可能依赖了很多其他依赖，此时，如果只对这个文件编译，那么会报错提示找不到对应的依赖，
* 而通过这个方法就可以解决这个问题的
*
*/
@Override
public Iterable list(Location location, String packageName, Set kinds, boolean recurse) throws IOException {
List result = new ArrayList<>(16);
// 先将原来的也加入进来
for (JavaFileObject javaFileObject : super.list(location, packageName, kinds, recurse)) {
result.add(javaFileObject);
}
// 这里要区分编译的Location以及编译的Kind
if (location == StandardLocation.CLASS_PATH && kinds.contains(JavaFileObject.Kind.CLASS)) {
// .class文件以及classPath下, 这里需要额外添加类加载器加载的JavaFileObject
for (JavaFileObject file : classLoader.listCharSequenceJavaFileObject()) {
if (file.getName().startsWith(packageName)) {
result.add(file);
}
}
} else if (location == StandardLocation.SOURCE_PATH && kinds.contains(JavaFileObject.Kind.SOURCE)) {
// .java文件以及编译路径下
for (JavaFileObject file : javaFileObjectMap.values()) {
if (file.getName().startsWith(packageName)) {
result.add(file);
}
}
}
return result;
}
/**
* 自定义方法,用于添加和缓存待编译的源文件对象
*/
public void addCharSequenceJavaFileObject(Location location, String packageName, String relativeName, CharSequenceJavaFileObject javaFileObject) {
javaFileObjectMap.put(determineKey(location, packageName, relativeName), javaFileObject);
}
/**
* 得到唯一key
*/
private static String determineKey(Location location, String packageName, String relativeName) {
return location.getName() + '/' + packageName + '/' + relativeName;
}
}