Java通过反射的方式进行热部署Demo

• • • jar生成
    • java程序通过反射的方式调用jar

接口及实现代码如下，maven项目，然后打包成jar，放入D:tmpjarjava-demo-1.0-SNAPSHOT.jar

package auto.deploy;

import java.util.List;
import java.util.Set;

public interface RuleProcessor {
    boolean process(List slots, Set filter);
}

package auto.deploy;

import java.util.List;
import java.util.Set;
public class GlobalPriorityRule implements RuleProcessor {

    @Override
    public boolean process(List slots, Set filter) {
        slots.set(0, getGlobalPriorityArticle());
        filter.add(getGlobalPriorityArticle());
        return true;
    }

    private String getGlobalPriorityArticle() {
        return "00000000";
    }
}

主项目也要有RuleProcessor.java

package auto.deploy;

import java.net.URL;
import java.net.URLClassLoader;
import java.util.*;

public class AutoDeployUtils {

    public static  T reflectByClass(String filename, String classname, Class tClass) throws Exception {
        URLClassLoader urlClassLoader = new URLClassLoader(new URL[]{new URL("file:/" + filename)},
                Thread.currentThread().getContextClassLoader());
        Class clazz = urlClassLoader.loadClass(classname);
        Object obj = clazz.newInstance();
        T entity = (T) obj;
        return entity;
    }

    public static void main(String[] args) throws Exception {
        String filename = "D:/tmp/jar/java-demo-1.0-SNAPSHOT.jar";
        String classname = "auto.deploy.GlobalPriorityRule";
        RuleProcessor rule = reflectByClass(filename, classname, RuleProcessor.class);
        List slots = new ArrayList<>(16);
        for (int i = 0; i < 8; i++) {
            slots.add(null);
        }
        Set filter = new HashSet<>();
        boolean process = rule.process(slots, filter);
        // global priority result: slots = [00000000, null, null, null, null, null, null, null], filter = [00000000], has process true
        // 可以看到第一个位置的文章是00000000，已经成功处理了
        System.out.println(String.format("global priority result: slots = %s, filter = %s, has process %s",
                Arrays.toString(slots.toArray()), Arrays.toString(filter.toArray()), process));
    }
}

注意jar包里接口和主项目里接口的定义要一致(包括包面要一致)
最终结果可以看到，按 “全局优先” 规则 填槽，直接将文章“00000000”填到了slots的第一个位置