JavaBean的toString方法工具类

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.LinkedHashMap;

public class ToStringUtils {

public static final String GET = "get";

/**
* 返回JavaBena的toString方法值
*
* @param t
* @return String
*/
public static <T> String getToString(T t) {
String result = null;
Field[] fields = t.getClass().getDeclaredFields(); // 获取实体类的所有属性，返回Field数组
LinkedHashMap<String, Object> map = new LinkedHashMap<String, Object>();
for (Field field : fields) {
field.setAccessible(true);
String name = field.getName(); // 获取属性的名字
Object value = getAttributeValue(t, name);// 获取属性值
map.put(name, value != null ? value : null);
name = null;
value = null;
}
result = map.toString();
fields = null;
map.clear();
map = null;
return result;
}

/**
* 返回JavaBena的toString方法值（只有属性的情况下）
*
* @param t
* @return String
*/
public static <T> String getToString1(T t) {
String result = null;
Field[] fields = t.getClass().getDeclaredFields(); // 获取实体类的所有属性，返回Field数组
LinkedHashMap<String, Object> map = new LinkedHashMap<String, Object>();
for (Field field : fields) {
try {
field.setAccessible(true);
map.put(field.getName(), field.get(t));
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
result = map.toString();
fields = null;
map.clear();
map = null;
return result;
}

/**
* 通过反射，用属性名称获得属性值
*
* @param t
* @param attributeName
* @return Object
*/
private static <T> Object getAttributeValue(T t, String attributeName) {
Object result = null;
Method method = null;
try {
StringBuffer methodName = new StringBuffer(GET);
methodName.append(attributeName.substring(0, 1).toUpperCase());
methodName.append(attributeName.substring(1));
method = t.getClass().getMethod(methodName.toString());
methodName = null;
result = method.invoke(t);
method = null;
} catch (NoSuchMethodException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SecurityException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return result;
}
}

public class BaseBean {
@Override
public String toString() {
// TODO Auto-generated method stub
return ToStringUtils.getToString(this);
}
}

public class TestBean extends BaseBean {

private int id;
private String name;

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}
}

public class Test {

public static void main(String[] args) {
TestBean testBean = new TestBean();
System.out.println("默认值：" + testBean.toString());
testBean.setId(10010);
testBean.setName("李四");
System.out.println("赋值之后：" + testBean.toString());
}
}