ClassUtils 常用方法总结

判断是否为转型

isAssignable(Class<?> cls, Class<?> toClass)等等

@Test

public void testIsAssignable(){

System.out.println("判断是否可以转型.");

System.out.println(ClassUtils.isAssignable(Date.class, Object.class)); //= true

System.out.println(ClassUtils.isAssignable( 《一线大厂 Java 面试题解析+后端开发学习笔记+最新架构讲解视频+实战项目源码讲义》无偿开源 威信搜索公众号【编程进阶路】 Object.class, Date.class)); //=false

}

判断是否为内部类

isInnerClass(Class<?> cls)

@Test

public void testIsInnerClass(){

System.out.println(ClassUtils.isInnerClass(Entry.class)); // = ture

System.out.println(ClassUtils.isInnerClass(Object.class)); //= false

}

判读是否为基础类型或者包装类型

isPrimitiveOrWrapper(Class<?> type)

isPrimitiveWrapper(Class<?> type)

@Test

public void testIsPrimitiveWrapper(){

// wrapper 类有(Boolean, Byte, Character, Short, Integer, Long, Double, Float).

System.out.println(ClassUtils.isPrimitiveWrapper(Integer.class)); // = ture

System.out.println(ClassUtils.isPrimitiveWrapper(Object.class)); // = false

System.out.println(ClassUtils.isPrimitiveWrapper(String.class)); // = false

System.out.println(ClassUtils.isPrimitiveWrapper(int.class)); // = false

System.out.println(ClassUtils.isPrimitiveOrWrapper(Integer.class)); // = ture

System.out.println(ClassUtils.isPrimitiveOrWrapper(Object.class)); // = false

System.out.println(ClassUtils.isPrimitiveOrWrapper(String.class)); // = false

System.out.println(ClassUtils.isPrimitiveOrWrapper(int.class)); // = true

}

基础类型和包装类型转换

wrapperToPrimitive(Class<?> cls)

@Test

public void testWrapperToPrimitive(){

System.out.println(ClassUtils.wrapperToPrimitive(Integer.class));// = int

}

获取类名和 class 类互转

convertClassesToClassNames(List<Class<?>> classes)

convertClassNamesToClasses(List<String> classNames)

对象转 Class 对象

toClass(Object... array)

@Test

public void testToClass(){

//类转化为 class 对象

Class[] classAry = ClassUtils.toClass(new String(),new Object());

System.out.println(ArrayUtils.toString(classAry));

// = {class java.lang.String,class java.lang.Object}

}

获取缩略名

getAbbreviatedName(Class<?> cls,int len)

getAbbreviatedName(String className,int len)

@Test

public void testGetAbbreviatedName(){

//获取类的缩略名称

String abbreviatedName1 = ClassUtils.getAbbreviatedName(String.class, 5);

String abbreviatedName2 = ClassUtils.getAbbreviatedName(String.class, 10);

String abbreviatedName3 = ClassUtils.getAbbreviatedName(String.class, 3);

String abbreviatedName4 = ClassUtils.getAbbreviatedName(String.class, 20);

System.out.println(abbreviatedName1);

System.out.println(abbreviatedName2);

System.out.println(abbreviatedName3);

System.out.println(abbreviatedName4);

}

获得所有实现的接口

getAllInterfaces(Class<?> cls)

@Test

public void testGetAllInterfaces(){

//获得所有实现的接口

List<Class<?>> classAry = ClassUtils.getAllInterfaces(String.class);

System.out.println(ArrayUtils.toString(classAry));

}

获取所有父类

getAllSuperclasses(Class<?> cls)

@Test

public void testGetAllSuperclasses(){

//获得所有的父类

List<Class<?>> classArray = ClassUtils.getAllSuperclasses(String.class);

System.out.println(ArrayUtils.toString(classArray));

//[class java.lang.Object]

}