bean通过反射重写toString

思路1：

网上一大把，通过this.getClass().getDeclaredFields();获得所有属性，禁掉访问限制，最终输出属性值

// public String toString2() {
//     System.out.println("enter sourceObj toString...");
//
//     StringBuffer sb = new StringBuffer();
//     Field[] fields = this.getClass().getDeclaredFields();
// for(Field iField : fields) {
// iField.setAccessible(true);
// sb.append(iField.getName());
// sb.append("=");
// try {
// sb.append(iField.get(this));
// }catch(IllegalArgumentException e) {
// e.printStackTrace();
// }catch(IllegalAccessException e) {
// e.printStackTrace();
// }
// sb.append("\n");
// }
// return sb.toString();
// }

思路2：
bean自身有public的get set方法，找到对应方法，截取名字，通过Method.invoke方法得到当前属性值

public  String toString(){
    System.out.println("SourceObj toString1...");

 Class<?> clazz = this.getClass();
 StringBuffer res = new StringBuffer(clazz.getSuperclass().getName() + " \n");
 for (; clazz != Object.class; clazz = clazz.getSuperclass()) {
 // System.out.println(clazz.getName());
 Method[] methods = clazz.getDeclaredMethods();
 for (int i = 0; i < methods.length; i++) {
 Method tmp = methods[i];
 String mName = tmp.getName();
 if (mName.startsWith("get")) {
 String fName = mName.substring(3);
 res.append(fName + " = ");
 try {
 Object o = tmp.invoke(this, null);
 if (o == null) {
 res.append(" null \n");
 continue;
 }
 if (o instanceof Double) {
 res.append("" + ((Double) o).doubleValue() + " \n");
 } else if (o instanceof Float) {
 res.append("" + ((Float) o).floatValue() + " \n");
 } else if (o instanceof Long) {
 res.append("" + ((Long) o).longValue() + " \n");
 } else if (o instanceof String) {
 res.append("" + (String) o + " \n");
 } else if (o instanceof Date) {
 res.append("" + ((Date) o).toString() + " \n");
 } else {
 res.append("" + o.toString() + " \n");
 }
 } catch (IllegalAccessException e) {
 continue;
 } catch (InvocationTargetException ex) {
 continue;
 }
 }
 }
 }
 return res.toString();
}

由于调用关系，需要注意getClass()获得的对象，this初始指向并不是bean本身。

bean：

public class SourceObj extends BaseObj{

    private String context;
 private String memo;
 private String source;

 public String getContext() { return context; }
 public void setContext(String context) { this.context = context; }
 public String getMemo() { return memo; }
 public void setMemo(String memo) { this.memo = memo; }
 public String getSource() { return source; }
 public void setSource(String source) { this.source = source; }
 
 public String toString(){...}
}