drools5入门（一）
安装drools5插件
直接解压drools-5.0-eclipse-all.zip到eclipse下的 dropins目录中。
建立一个Java Project。
引入drools必备的jar包
antlr-runtime-3.1.1.jar
core-3.4.2.v_883_R34x.jar
drools-api-5.0.1.jar
drools-compiler-5.0.1.jar
drools-core-5.0.1.jar
mvel2-2.0.10.jar
创建一个User的POJO类：
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package com.test;
publicclass User {
private String loginName;
public String getLoginName() { returnloginName; }
publicvoid setLoginName(String loginName) { this.loginName = loginName; }
@Override publicint hashCode() { finalint prime = 31; int result = 1; result = prime * result + ((loginName == null) ? 0 : loginName.hashCode()); return result; }
@Override publicboolean equals(Object obj) { if (this == obj) returntrue; if (obj == null) returnfalse; if (getClass() != obj.getClass()) returnfalse; User other = (User) obj; if (loginName == null) { if (other.loginName != null) returnfalse; } elseif (!loginName.equals(other.loginName)) returnfalse; returntrue; }
@Override public String toString() { return"User [loginName=" + loginName + "]"; } }
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新建一个规则定义文件
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package com.test;
rule"rule_01" when $user : User(loginName != null) then System.out.println("hello, " + $user.getLoginName()); end |
最后写一个RuleApp规则启动类：
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package com.test;
import org.drools.KnowledgeBase; import org.drools.KnowledgeBaseFactory; import org.drools.builder.KnowledgeBuilder; import org.drools.builder.KnowledgeBuilderFactory; import org.drools.builder.ResourceType; import org.drools.io.ResourceFactory; import org.drools.runtime.StatefulKnowledgeSession;
publicclass RuleApp {
publicstaticvoid main(String[] args) { KnowledgeBase knowledgeBase = createKnowledgeBase(); StatefulKnowledgeSession session = knowledgeBase .newStatefulKnowledgeSession(); try { User user = new User(); user.setLoginName("zhangsan"); session.insert(user); session.fireAllRules(); } finally { session.dispose(); } }
privatestatic KnowledgeBase createKnowledgeBase() { KnowledgeBuilder builder = KnowledgeBuilderFactory .newKnowledgeBuilder(); builder.add(ResourceFactory.newClassPathResource("helloworld.drl", User.class), ResourceType.DRL); if (builder.hasErrors()) { thrownew RuntimeException(builder.getErrors().toString()); } KnowledgeBase knowledgeBase = KnowledgeBaseFactory.newKnowledgeBase(); knowledgeBase.addKnowledgePackages(builder.getKnowledgePackages()); return knowledgeBase; }
}
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测试输出
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hello, zhangsan |