Essays-java Annotations, Reflections, enumerations

Package aresoft.controller.test;

Import java.lang.annotation.Annotation;
Import Java.lang.reflect.Constructor;
Import Java.lang.reflect.Field;
Import Java.lang.reflect.Method;
Import java.util.ArrayList;
Import java.util.List;

public class Demo3 {
@SuppressWarnings ("Unchecked")
public static <T> void Test () {
try {
1, Load Class
Class clazz=class.forname ("Aresoft.controller.test.DemoBean");
2. Get the corresponding constructor object according to the constructor parameter type
Constructor CSR = Clazz.getconstructor (String[].class);
String str[]={"1", "testname", "Man"};
3. Create an Entity object
t T1 = (t) csr.newinstance ((Object) str);

List<field> Fieldlist=getfields (Clazz);
int flag=0;
Object Obj=null;
for (Field f:fieldlist) {
if (Isclasstype (f)) {
flag=flag+1;
Method Method=commonmethod (Meiju.GET.getName (), clazz,f);
System.out.println (Method.getreturntype ());
if (!method.getreturntype (). toString (). Equals ("void")) {
Obj=method.invoke (T1,new object[]{});
}
System.out.println (Obj.tostring ());

if (flag>2) {
Break
}
Annotation[] As=f.getannotations (); Comments for each field
if (As.length >=0) {
for (Annotation A:As) {
System.out.println ("Annotation:" +a.tostring ());
}
}
}
}


Method annotations
Zhujie Zjmethod=clazz.getmethod (Commonmethod (Meiju.GET.getName (), Clazz,fieldlist.get (1)). GetName (), New class[]{} ). Getannotation (Zhujie.class);
Note System.out.println ("GetName () Method:" +zjmethod.name ());
field annotations
Zhujie Zjfield=clazz.getdeclaredfield ((Fieldlist.get (1)). GetName ()). Getannotation (Zhujie.class);
System.out.println ("Name field annotation:" +zjfield.name ());


Gets or sets whether the method is preceded by an enumeration
Method Setmethod=commonmethod (Meiju.SET.getName (), Clazz,fieldlist.get (3));
if (Setmethod.getreturntype (). toString (). Equals ("void")) {//If return type void
System.out.println ("No return type");
}
Integer i=new integer (1);
Setmethod.invoke (T1,i);
} catch (Exception e) {
E.printstacktrace ();
}
}

Get all the field including the parent class
public static list<field> GetFields (class<?> clazz) {
List<field> fieldlist=new arraylist<field> ();
bo=
Field[] Fields=clazz.getdeclaredfields ();
for (Field f:fields) {
Fieldlist.add (f);
}
Clazz=clazz.getsuperclass ();
}while (clazz! = Object.class && clazz!=null);
return fieldlist;
}

Determine if field is a basic type
public static Boolean isclasstype (Field field) {
Class<?> Type=field.gettype ();
Boolean Isbaseclass=false;
if (type.isprimitive () | | | type.getpackage ()!=null
|| Type.getpackage (). GetName (). Equals ("Java.lang")
|| Type.getpackage (). GetName (). Equals ("Java.math")
|| Type.getpackage (). GetName (). Equals ("Java.math")) {
Isbaseclass=true;
}else if (Type.isarray ()) {
Isbaseclass=false;
}
return isbaseclass;
}

Method get
public static Method GetMethod (class<?> Clazz,field Field) {
StringBuffer SB =new stringbuffer ();
Sb.append (Meiju.GET.getName ());
Method Method=null;
try {
String firstchar=field.getname (). substring (0, 1). toUpperCase ();
Sb.append (Firstchar);
Sb.append (Field.getname (). substring (1, field.getname (). Length ());
Method=clazz.getdeclaredmethod (Sb.tostring (), New class[]{});
} catch (Exception e) {
E.printstacktrace ();
}
return method;
}

Method Set
public static Method Setmethod (class<?> Clazz,field Field) {
StringBuffer SB =new stringbuffer ();
Sb.append (Meiju.SET.getName ());
Method Method=null;
try {
String firstchar=field.getname (). substring (0, 1). toUpperCase ();
Sb.append (Firstchar);
Sb.append (Field.getname (). substring (1, field.getname (). Length ());
Method=clazz.getdeclaredmethod (Sb.tostring (), Field.gettype ());
} catch (Exception e) {
E.printstacktrace ();
}
return method;
}

Method Common
public static Method Commonmethod (String gsmethod,class<?> Clazz,field Field) {
StringBuffer SB =new stringbuffer ();
Sb.append (Gsmethod);//get or set
Method Method=null;
try {
String firstchar=field.getname (). substring (0, 1). toUpperCase ();
Sb.append (Firstchar);
Sb.append (Field.getname (). substring (1, field.getname (). Length ());
if (Gsmethod.equals (Meiju.GET.getName ())) {
Method=clazz.getdeclaredmethod (Sb.tostring (), New class[]{});
}else if (Gsmethod.equals (Meiju.SET.getName ())) {
Method=clazz.getdeclaredmethod (Sb.tostring (), Field.gettype ());
}
} catch (Exception e) {
E.printstacktrace ();
}
return method;
}

public static void Main (string[] args) {
Test ();
}
}

Entity class

Package aresoft.controller.test;

Import Javax.persistence.Column;

@Zhujie (name= "Jeecg_demo")
public class Demobean {
/**id*/
@Zhujie (name= "id")
Private String ID;
/** Name * *
@Zhujie (name= "name")
private String name;
/** Sex * *
Private String sex;
/** Age */
Private Integer age;
Public String getId () {
return ID;
}
public void SetId (String id) {
This.id = ID;
}
@Zhujie (name= "Jeecg_demo_method")
Public String GetName () {
return name;
}
public void SetName (String name) {

THIS.name = name;
}
Public String Getsex () {
return sex;
}
public void Setsex (String sex) {
This.sex = sex;
}
Public Integer Getage () {
return age;
}
public void Setage (Integer age) {
This.age = age;
}
Public Demobean (string[] String) {
Super ();
This.id = string[0];
THIS.name = string[1];

This.sex = string[2];

}
Public Demobean () {
Super ();
TODO auto-generated Constructor stub
}

}

Annotations

Package aresoft.controller.test;

Import static Java.lang.annotation.ElementType.CONSTRUCTOR;
Import static Java.lang.annotation.ElementType.FIELD;
Import static Java.lang.annotation.ElementType.LOCAL_VARIABLE;
Import static Java.lang.annotation.ElementType.METHOD;
Import static Java.lang.annotation.ElementType.PARAMETER;
Import static Java.lang.annotation.ElementType.TYPE;

Import java.lang.annotation.Retention;
Import Java.lang.annotation.RetentionPolicy;
Import Java.lang.annotation.Target;

@Target ({TYPE, FIELD, METHOD, PARAMETER, CONSTRUCTOR, local_variable})
@Retention (Retentionpolicy.runtime)
Public @interface Zhujie {
String name () default "test";

}

Enumeration

Package aresoft.controller.test;

public enum Meiju {
Get ("Get"), set ("Set");
private String name;



Private Meiju (String name) {
THIS.name = name;
}

Public String GetName () {
return name;
}

public void SetName (String name) {
THIS.name = name;
}

}

Essays-java Annotations, Reflections, enumerations