责任链设计模式学习

1，xml设置

<?xml version="1.0" encoding="UTF-8"?>
<catalog>
    <chain name="myChaia"
className="com.zr.alibaba.template.chain.test">
        <command id="B"
className="com.zr.alibaba.template.chain.test.chain.command.SetTestCommand" />
        <command id="C" className="com.zr.alibaba.template.chain.teste.chain.command.SetTest2Command" />
    </chain>
</catalog>

2,基础命令

public interface BaseCommand extends Command<String, Object, JSONObject>
{
    /**
     * 覆盖执行方法
     *
     * @param context
     * @return
     */
    @Override
    default Processing execute1(JSONObject context)
    {
        this.doExecute(context);
        return Processing.CONTINUE;
    }

    /**
     * 实际执行方法
     *
     * @param context
     */
    void doExecute2(JSONObject context);
}

3，基础链

public class BaseChain extends ChainBase<String, Object, JSONObject>
{
    @Override
    public Processing execute(JSONObject context)
    {
        try
        {
            return super.execute(context);
        }
        catch (ChainException e)
        {
            log.error(e.getMessage(), e);
            throw new RuntimeException(Optional.ofNullable(e.getCause()).map(ExceptionUtil::getMessage)
                    .orElse(e.getMessage()));
        }
    }
}

4，加载配置这个要用到springbot的自动加载 spring.factories 来加载文件全限定包名

TaskConfig

package com.bessky.common.task;

import com.xxl.job.core.executor.impl.XxlJobSpringExecutor;
import org.apache.commons.chain2.config.xml.XmlConfigParser;
import org.apache.commons.digester3.Digester;
import org.apache.commons.digester3.ObjectCreateRule;
import org.apache.commons.digester3.RuleSet;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.xml.sax.Attributes;

import javax.annotation.Resource;
import java.net.URL;
import java.util.Enumeration;


@Configuration
public class TaskConfig implements InitializingBean
{
    @Resource
    private ApplicationContext applicationContext;

    @Bean
    @ConfigurationProperties("xxl.job.executor")
    @ConditionalOnProperty("xxl.job.executor.adminaddresses")
    public XxlJobSpringExecutor xxlJobExecutor()
    {
        return new XxlJobSpringExecutor();
    }

    @Override
    public void afterPropertiesSet() throws Exception
    {
        Enumeration<URL> enumeration = this.getClass().getClassLoader().getResources("chain-config.xml");

        if (!enumeration.hasMoreElements())
        {
            return;
        }

        XmlConfigParser parser = new XmlConfigParser()
        {
            @Override
            public Digester getDigester()
            {
                Digester digester = new Digester()
                {
                    @Override
                    public void addObjectCreate(String pattern, String className, String attributeName)
                    {
                        addRule(pattern, new ObjectCreateRule(className, attributeName)
                        {
                            @Override
                            public void begin(String namespace, String name, Attributes attributes) throws Exception
                            {
                                String className = attributes.getValue(this.attributeName);
                                if (className != null)
                                {
                                    Class<?> clazz = this.getDigester().getClassLoader().loadClass(className);
                                    Object object = applicationContext.getBean(clazz);
                                    this.getDigester().push(object);
                                    return;
                                }
                                super.begin(namespace, name, attributes);
                            }
                        });
                    }
                };
                RuleSet ruleSet = this.getRuleSet();
                digester.setNamespaceAware(ruleSet.getNamespaceURI() != null);
                digester.setUseContextClassLoader(this.getUseContextClassLoader());
                digester.setValidating(false);
                digester.addRuleSet(ruleSet);
                return digester;
            }
        };

        do
        {
            parser.parse(enumeration.nextElement());
        }
        while (enumeration.hasMoreElements());
    }
}

 

一般定时任务里面就可以调用自定义业务链chain

MyJobHandler  etends BaseJobHandler----> MyChain .execute(用上下文set值)---->会自动执行多个conmmond