java自动生成类热加载（注册和扫描）-阿里云开发者社区

背景

从简单工厂到工厂方法（参考大话设计模式）

将实际的业务封装到了具体的子类中，但是如果无法生成各个子工厂的代码，这种封装还是缺点意思。于是现在想直接根据operation子类生成工厂部分的代码。

实操

1、扫描方式

package PassivehotLoad;
import javax.tools.JavaCompiler;
import javax.tools.ToolProvider;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.nio.file.*;
import java.util.*;
/**
 * @BelongsProject: JAVAtest
 * @BelongsPackage: hotLoad
 * @Author: GuoYuan.Zhao
 * @CreateTime: 2023-03-18  10:17
 * @Description: TODO
 * @Version: 1.0
 */
public class MyManagerHot {
    static String className = "";
    static String operation = "";
    static List<String>allName ;
    public static void main(String[] args) throws ClassNotFoundException, InvocationTargetException, InstantiationException, IllegalAccessException, NoSuchMethodException, IOException {
        //首先去扫描OperationAll包下是不是多了类，如果类变多了，从类中提起关键字 如Add，然后将值赋值给变量，然后按照下面的步骤进行
        String pathPackage = "E:\\zy\\TGB-zgy-2022\\米老师设计模式课相关资料必须留着\\米老师设计模式课小例子\\JAVAtest\\Factory\\src\\main\\java\\MoreAutoFactory\\OperationAll";
        File file = new File(pathPackage);
        if (file.isDirectory()){
            List<String>allNameNew = null;
            File[] files = file.listFiles();
            for (File f : files) {
                String fileName = f.getAbsolutePath();
                if (fileName.endsWith(".java")) {
                    String className = fileName.substring(fileName.indexOf("MoreAutoFactory"), fileName.indexOf(".java"));
                    String replacedName = className.replace("MoreAutoFactory\\OperationAll\\Operation", "");
//                    allNameNew.add(replacedName);
                    create(replacedName);
                    reflect(replacedName);
                }
            }
        }
    }
    public static void create(String className) throws IOException {
        Scanner scanner = new Scanner(System.in);
//        System.out.println("请输入要创建的算法的模式：");
//        className = scanner.nextLine();
        if(className.equals("Add")){
            operation = "+";
        }else if (className.equals("Sub")){
            operation = "-";
        }else if (className.equals("Mul")){
            operation = "*";
        }else if (className.equals("Div")){
            operation = "/";
        }
        String srcOperationCode =
                "package MoreAutoFactory.OperationAll;\n" +
                        "\n" +
                        "\n" +
                        "import MoreAutoFactory.Operation;\n" +
                        "\n" +
                        "public class Operation"+className+" extends Operation {\n" +
                        "    @Override\n" +
                        "    public  double getResult(){\n" +
                        "        double result = 0;\n" +
                        "        result  = getNumberA()"+operation+"getNumberB();\n" +
                        "        return result;\n" +
                        "    }\n" +
                        "\n" +
                        "}";
        //要创建文件的路径
        String path1 = "E:\\zy\\TGB-zgy-2022\\米老师设计模式课相关资料必须留着\\米老师设计模式课小例子\\JAVAtest\\Factory\\src\\main\\java\\MoreAutoFactory\\OperationAll\\Operation"+ className+".java";
        File file1 = new File(path1);
        if (!file1.exists()) {
            if (file1.createNewFile()) {
                System.out.println("新类型算法文件创建成功");
                FileWriter fileWriter = new FileWriter(path1);
                BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
                bufferedWriter.write(srcOperationCode);
                bufferedWriter.close();
                //编译文件
                Compiler(System.getProperty("user.dir")+"\\Factory\\target\\classes",path1);
            }
        }
        String srcFactoryCode =
                "package MoreAutoFactory.FactoryAll;\n" +
                        "\n" +
                        "import MoreAutoFactory.IFactory;\n" +
                        "import MoreAutoFactory.Operation;\n" +
                        "import MoreAutoFactory.OperationAll.Operation"+className+";\n" +
                        "\n" +
                        "public class "+className+"Factory implements IFactory {\n" +
                        "    @Override\n" +
                        "    public Operation createOperation() {\n" +
                        "        return new Operation"+className+"();\n" +
                        "    }\n" +
                        "}";
        //要创建文件的路径
        String path = "E:\\zy\\TGB-zgy-2022\\米老师设计模式课相关资料必须留着\\米老师设计模式课小例子\\JAVAtest\\Factory\\src\\main\\java\\MoreAutoFactory\\FactoryAll\\" + className + "Factory.java";
        File file = new File(path);
        if (!file.exists()) {
            if (file.createNewFile()) {
                System.out.println("新类型工厂文件创建成功");
                FileWriter fileWriter = new FileWriter(path);
                BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
                bufferedWriter.write(srcFactoryCode);
                bufferedWriter.close();
                //编译文件
                Compiler(System.getProperty("user.dir")+"\\Factory\\target\\classes",path);
            }
        }
        String srcClientCode =
                "package MoreAutoFactory.ClientAll;\n" +
                        "\n" +
                        "import MoreAutoFactory.FactoryAll."+className+"Factory;\n" +
                        "import MoreAutoFactory.IFactory;\n" +
                        "import MoreAutoFactory.Operation;\n" +
                        "\n" +
                        "public class "+className+"Client {\n" +
                        "  public  void getEndResult() throws Exception {\n" +
                        "      IFactory operFactory = new "+className+"Factory();\n" +
                        "      Operation oper = operFactory.createOperation();\n" +
                        "       oper.setNumberA(2);\n" +
                        "       oper.setNumberB(2);\n" +
                        "       double result = oper.getResult();\n" +
//                        "        System.out.println("+className+");\n" +
                        "        System.out.println(result);\n" +
                        "    }\n" +
                        "}";
        //要创建文件的路径
        String pathClient = "E:\\zy\\TGB-zgy-2022\\米老师设计模式课相关资料必须留着\\米老师设计模式课小例子\\JAVAtest\\Factory\\src\\main\\java\\MoreAutoFactory\\ClientAll\\" + className + "Client.java";
        File fileClient = new File(pathClient);
        if (!fileClient.exists()) {
            if (fileClient.createNewFile()) {
                System.out.println("新类型客户端文件创建成功");
                FileWriter fileWriter = new FileWriter(pathClient);
                BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
                bufferedWriter.write(srcClientCode);
                bufferedWriter.close();
                //编译文件
                Compiler(System.getProperty("user.dir")+"\\Factory\\target\\classes",pathClient);
            }
        }
    }
    public static void reflect(String className) throws ClassNotFoundException, InstantiationException, IllegalAccessException, InvocationTargetException, NoSuchMethodException {
//            String str = "MoreAutoFactory.Client"+className+"Client";
//            System.out.println(str);
        Class classClient = Class.forName("MoreAutoFactory.ClientAll."+className+"Client");
        Object object = classClient.newInstance();
        Method getEndResultMethod = classClient.getMethod("getEndResult");
        getEndResultMethod.invoke(object,null);
    }
    public static void Compiler(String compilerPath,String javaPath){
        JavaCompiler javac = ToolProvider.getSystemJavaCompiler();
        int status = javac.run(null, null, null, "-d",
                compilerPath,javaPath);
        if(status!=0){
            System.out.println("没有编译成功！");
        }
    }
}

2、注册方式

package twoMethodCreateClass.Register;
import hotLoad.BaseManager;
import javax.tools.JavaCompiler;
import javax.tools.ToolProvider;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Scanner;
/**
 * @BelongsProject: JAVAtest
 * @BelongsPackage: hotLoad
 * @Author: GuoYuan.Zhao
 * @CreateTime: 2023-03-18  10:17
 * @Description: TODO
 * @Version: 1.0
 */
public class MyManagerHot {
    public static void main(String[] args) throws IOException, ClassNotFoundException, InvocationTargetException, InstantiationException, IllegalAccessException, NoSuchMethodException {
        create();
        reflect();
    }
        static String className = "";
        static String operation = "";
    public static void create() throws IOException {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入要创建的算法的模式：");
        className = scanner.nextLine();
        if(className.equals("Add")){
            operation = "+";
        }else if (className.equals("Sub")){
            operation = "-";
        }else if (className.equals("Mul")){
            operation = "*";
        }else if (className.equals("Div")){
            operation = "/";
        }
        String srcOperationCode =
                "package MoreAutoFactory.OperationAll;\n" +
                        "\n" +
                        "\n" +
                        "import MoreAutoFactory.Operation;\n" +
                        "\n" +
                        "public class Operation"+className+" extends Operation {\n" +
                        "    @Override\n" +
                        "    public  double getResult(){\n" +
                        "        double result = 0;\n" +
                        "        result  = getNumberA()"+operation+"getNumberB();\n" +
                        "        return result;\n" +
                        "    }\n" +
                        "\n" +
                        "}";
        //要创建文件的路径
        String path1 = "E:\\zy\\TGB-zgy-2022\\米老师设计模式课相关资料必须留着\\米老师设计模式课小例子\\JAVAtest\\Factory\\src\\main\\java\\MoreAutoFactory\\OperationAll\\Operation"+ className+".java";
        File file1 = new File(path1);
        if (!file1.exists()) {
            if (file1.createNewFile()) {
                System.out.println("新类型算法文件创建成功");
                FileWriter fileWriter = new FileWriter(path1);
                BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
                bufferedWriter.write(srcOperationCode);
                bufferedWriter.close();
                //编译文件
                Compiler(System.getProperty("user.dir")+"\\Factory\\target\\classes",path1);
            }
        }
        String srcFactoryCode =
                "package MoreAutoFactory.FactoryAll;\n" +
                        "\n" +
                        "import MoreAutoFactory.IFactory;\n" +
                        "import MoreAutoFactory.Operation;\n" +
                        "import MoreAutoFactory.OperationAll.Operation"+className+";\n" +
                        "\n" +
                        "public class "+className+"Factory implements IFactory {\n" +
                        "    @Override\n" +
                        "    public Operation createOperation() {\n" +
                        "        return new Operation"+className+"();\n" +
                        "    }\n" +
                        "}";
        //要创建文件的路径
        String path = "E:\\zy\\TGB-zgy-2022\\米老师设计模式课相关资料必须留着\\米老师设计模式课小例子\\JAVAtest\\Factory\\src\\main\\java\\MoreAutoFactory\\FactoryAll\\" + className + "Factory.java";
        File file = new File(path);
        if (!file.exists()) {
            if (file.createNewFile()) {
                System.out.println("新类型工厂文件创建成功");
                FileWriter fileWriter = new FileWriter(path);
                BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
                bufferedWriter.write(srcFactoryCode);
                bufferedWriter.close();
                //编译文件
                Compiler(System.getProperty("user.dir")+"\\Factory\\target\\classes",path);
            }
        }
        String srcClientCode =
                "package MoreAutoFactory.ClientAll;\n" +
                        "\n" +
                        "import MoreAutoFactory.FactoryAll."+className+"Factory;\n" +
                        "import MoreAutoFactory.IFactory;\n" +
                        "import MoreAutoFactory.Operation;\n" +
                        "\n" +
                        "public class "+className+"Client {\n" +
                        "  public  void getEndResult() throws Exception {\n" +
                        "      IFactory operFactory = new "+className+"Factory();\n" +
                        "      Operation oper = operFactory.createOperation();\n" +
                        "       oper.setNumberA(2);\n" +
                        "       oper.setNumberB(2);\n" +
                        "       double result = oper.getResult();\n" +
                        "        System.out.println(result);\n" +
                        "    }\n" +
                        "}";
        //要创建文件的路径
        String pathClient = "E:\\zy\\TGB-zgy-2022\\米老师设计模式课相关资料必须留着\\米老师设计模式课小例子\\JAVAtest\\Factory\\src\\main\\java\\MoreAutoFactory\\ClientAll\\" + className + "Client.java";
        File fileClient = new File(pathClient);
        if (!fileClient.exists()) {
            if (fileClient.createNewFile()) {
                System.out.println("新类型客户端文件创建成功");
                FileWriter fileWriter = new FileWriter(pathClient);
                BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
                bufferedWriter.write(srcClientCode);
                bufferedWriter.close();
                //编译文件
                Compiler(System.getProperty("user.dir")+"\\Factory\\target\\classes",pathClient);
            }
        }
    }
        public static void reflect() throws ClassNotFoundException, InstantiationException, IllegalAccessException, InvocationTargetException, NoSuchMethodException {
//            String str = "MoreAutoFactory.Client"+className+"Client";
//            System.out.println(str);
            Class classClient = Class.forName("MoreAutoFactory.ClientAll."+className+"Client");
            Object object = classClient.newInstance();
            Method getEndResultMethod = classClient.getMethod("getEndResult");
            getEndResultMethod.invoke(object,null);
        }
        public static void Compiler(String compilerPath,String javaPath){
            JavaCompiler javac = ToolProvider.getSystemJavaCompiler();
            int status = javac.run(null, null, null, "-d",
 compilerPath,javaPath);
            if(status!=0){
                System.out.println("没有编译成功！");
            }
        }
}

总结

代码分为三种

源码

字节码

机器码

我们可以通过改变源码的方式去操纵机器码，这也是实现自动化的关键

java自动生成类热加载（注册和扫描）

背景

实操

1、扫描方式

2、注册方式

总结

热门文章

最新文章

相关课程

相关电子书

相关实验场景

热门

活动广场

任务中心

开发者评测

高校计划

乘风者计划

训练营

阿里云MVP

话题

直播

下载

镜像站

技术资料

插件

java自动生成类热加载（注册和扫描）

背景

实操

1、扫描方式

2、注册方式

总结

热门文章

最新文章

相关课程

相关电子书

相关实验场景