com.youthlin.ioc.annotaion.AnnotationUtil Maven / Gradle / Ivy
package com.youthlin.ioc.annotaion;
import com.youthlin.ioc.exception.NoSuchBeanException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.annotation.Resource;
import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
/**
* 创建： youthlin.chen
* 时间： 2017-08-10 14:48.
*/
@SuppressWarnings("WeakerAccess")
public class AnnotationUtil {
private static final Logger LOGGER = LoggerFactory.getLogger(AnnotationUtil.class);
private static final String FILE_SEPARATOR = System.getProperty("file.separator", "/");
private static final String DOT_CLASS = ".class";
private static final String DOLLAR = "$";
private static final String DOT = ".";
private static final FileFilter FILE_FILTER = new FileFilter() {
@Override public boolean accept(File pathname) {
if (pathname.isDirectory()) {
return true;
}
String name = pathname.getName();
return !name.contains(DOLLAR) && name.endsWith(DOT_CLASS);
}
};
/**
* 获取包路径之下的所有类名 不包括内部类和非 .class 结尾的类
*/
static Set getClassNames(String... basePackages) {
Set classNames = new HashSet<>();
if (basePackages != null) {
for (String basePackage : basePackages) {
classNames.addAll(getClassNames(basePackage));
}
}
return classNames;
}
private static List getClassNames(String basePackage) {
List classNames = new ArrayList<>();
try {
Enumeration systemResources = ClassLoader.getSystemResources(basePackage.replace(DOT, FILE_SEPARATOR));
while (systemResources.hasMoreElements()) {
URL url = systemResources.nextElement();
if (url != null) {
classNames.addAll(getClassNamesFromUrl(basePackage, url));
}
}
} catch (IOException ignore) {
}
return classNames;
}
private static List getClassNamesFromUrl(String basePackage, URL url) {
List classNames = new ArrayList<>();
LOGGER.debug("scan url = {}", url);
String protocol = url.getProtocol();
switch (protocol) {
case "file":
classNames.addAll(getClassNamesFromFileSystem(basePackage, url));
break;
case "jar":
classNames.addAll(getClassNamesFromJar(basePackage, url));
break;
default:
LOGGER.warn("unknown protocol. [{}]", protocol);
}
return classNames;
}
private static List getClassNamesFromFileSystem(String basePackage, URL url) {
List classNames = new ArrayList<>();
String fileName = url.getFile();
fileName = fileName.replace("%20", " ");
File file = new File(fileName);
File[] files = file.listFiles(FILE_FILTER);
if (files != null) {
for (File file1 : files) {
classNames.addAll(getClassNamesFromFileSystem(basePackage, file1));
}
}
return classNames;
}
private static List getClassNamesFromFileSystem(String packageName, File file) {
List classNames = new ArrayList<>();
String fileName = file.getName();
if (file.isDirectory()) {
File[] files = file.listFiles(FILE_FILTER);
if (files == null) {
return Collections.emptyList();
}
for (File classFile : files) {
if (packageName.length() == 0) {
classNames.addAll(getClassNamesFromFileSystem(fileName, classFile));
} else {
classNames.addAll(getClassNamesFromFileSystem(packageName + DOT + fileName, classFile));
}
}
} else {
LOGGER.trace("package:{} class:{}", packageName, fileName);
classNames.add(packageName + DOT + fileName.substring(0, fileName.lastIndexOf(DOT_CLASS)));
}
return classNames;
}
private static List getClassNamesFromJar(String basePackage, URL url) {
List classNames = new ArrayList<>();
String jarFileName = url.toString();
jarFileName = jarFileName.replace("%20", " ");
jarFileName = jarFileName.substring("jar:file:".length());
int indexOf = jarFileName.indexOf("!/");
if (indexOf > 0) {
jarFileName = jarFileName.substring(0, indexOf);
}
try {
JarFile jarFile = new JarFile(jarFileName);
Enumeration entries = jarFile.entries();
while (entries.hasMoreElements()) {
JarEntry jarEntry = entries.nextElement();
String name = jarEntry.getName();
if (name.endsWith(DOT_CLASS) && !name.contains(DOLLAR) && name.startsWith(basePackage)) {
name = name.replace(FILE_SEPARATOR, DOT);
name = name.substring(0, name.lastIndexOf(DOT_CLASS));
classNames.add(name);
}
}
} catch (IOException e) {
throw new RuntimeException(e);
}
return classNames;
}
/**
* 获取字段上注解的名称
*
* @return 如果注解定义了名称，直接返回；否则返回空字符串
*/
static String getAnnotationName(Field field) {
Bean bean = field.getAnnotation(Bean.class);
Resource resource = field.getAnnotation(Resource.class);
String name = "";
if (bean != null) {
name = bean.value();
} else if (resource != null) {
name = resource.name();
}
return name;
}
/**
* 获取注解中定义的名称.
*
* @return 如果注解定义了名称，返回名称，否则返回类名
* @throws IllegalArgumentException 当类没有被注解时
*/
static String getAnnotationName(Class clazz) {
Bean beanAnnotation = clazz.getAnnotation(Bean.class);
Resource resourceAnnotation = clazz.getAnnotation(Resource.class);
if (beanAnnotation == null && resourceAnnotation == null) {
throw new IllegalArgumentException("No @Bean or @Resource annotation at this object.");
}
String name;
if (beanAnnotation != null) {
name = beanAnnotation.value();
} else {
name = resourceAnnotation.name();
}
if (name.isEmpty()) {
name = clazz.getSimpleName();
}
return name;
}
/**
* 获取字段的泛型类型.
*
* @param field 要处理的字段
* @param index 泛型列表中第几个, 0开始. 如{@code Map map} 0 表示第一个 String.class, 1 表示第二个 Object.class
* @return 泛型的类型
* @throws IllegalArgumentException 当字段不是泛型时
* @throws IndexOutOfBoundsException 当下标越界时
*/
public static Class getGenericClass(Field field, int index) {
Type genericType = field.getGenericType();
if (genericType instanceof ParameterizedType) {
Type type = ((ParameterizedType) genericType).getActualTypeArguments()[index];
if (Class.class.isAssignableFrom(type.getClass())) {
return (Class) type;
}
throw new IllegalArgumentException("Field has more than one level of generic");
}
throw new IllegalArgumentException("field is not generic: " + field);
}
public static T getBean(Map clazzBeanMap, Class clazz) {
List list = getBeans(clazzBeanMap, clazz);
if (list.isEmpty()) {
throw new NoSuchBeanException(clazz.getName());
}
if (list.size() == 1) {
return list.get(0);
}
throw new NoSuchBeanException("find more than one bean with type: " + clazz.getName());
}
@SuppressWarnings("unchecked")
public static List getBeans(Map clazzBeanMap, Class clazz) {
List list = new ArrayList<>();
T o = (T) clazzBeanMap.get(clazz);
if (o != null) {
list.add(o);
} else {
for (Map.Entry entry : clazzBeanMap.entrySet()) {
Class aClass = entry.getKey();
if (clazz.isAssignableFrom(aClass)) {
//该类可以赋值给 clazz (即，是 clazz 的子类)
list.add((T) entry.getValue());
}
}
}
return list;
}
@SuppressWarnings("unchecked")
public static Map getBeansMap(Map clazzBeanMap, Class clazz) {
Map map = new HashMap<>();
T o = (T) clazzBeanMap.get(clazz);
if (o != null) {
String name = AnnotationUtil.getAnnotationName(o.getClass());
map.put(name, o);
} else {
for (Map.Entry entry : clazzBeanMap.entrySet()) {
Class aClass = entry.getKey();
if (clazz.isAssignableFrom(aClass)) {
//aClass 类可以赋值给 clazz (aClass 是 clazz 的子类)
String name = AnnotationUtil.getAnnotationName(aClass);
map.put(name, (T) entry.getValue());
}
}
}
return map;
}
}
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