【Java】Java 反射 object is not an instance of declaring cla

【Java】Java 反射 object is not an instance of declaring class

1.背景

我想用Java反射出一个类的方法，并且传参执行

public class MetricInFields implements Serializable {

public RowTypeInfo getRowFields(SqlSessionFactory sqlSessionFactory, String dicName){

RowTypeInfo rowTypeInfo = new RowTypeInfo();

return rowTypeInfo;

}

}

测试代码如下

Class> clazz = Class.forName(className);

Method method = clazz.getMethod("getRowFields", SqlSessionFactory.class, String.class);

rowTypeInfo = (RowTypeInfo) method.invoke(null,factory,dicName);

但是报错空指针异常，然后我随便在invoke第一个参数传递的的时候，传入当前类报错

Caused by: java.lang.IllegalArgumentException: object is not an instance of declaring class

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)

后来发现，当反射静态方法的时候，直接传入Null就可以了，但是如果不是静态了，如下

public class MetricInFields implements Serializable {

public static RowTypeInfo getRowFields(SqlSessionFactory sqlSessionFactory, String dicName){

RowTypeInfo rowTypeInfo = new RowTypeInfo();

return rowTypeInfo;

}

}

如果不是静态类，如下

public class MetricInFields implements Serializable {

public RowTypeInfo getRowFields(SqlSessionFactory sqlSessionFactory, String dicName){

RowTypeInfo rowTypeInfo = new RowTypeInfo();

return rowTypeInfo;

}

}

那么可以这样

Class> clazz = Class.forName(className);

Object obj = clazz.newInstance();

Method method = clazz.getMethod("getRowFields", SqlSessionFactory.class, String.class);

rowTypeInfo = (RowTypeInfo) method.invoke(null,factory,dicName);

【Java】Java 反射 object is not an instance of declaring cla相关教程