[开发工具]java 自定义表达式 表达式解析 QLExpress使用

具体使用语法规则可以查看下面地址中文档说明：
QLExpress：https://github.com/alibaba/QLExpress

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>QLExpress</artifactId>
            <version>3.2.0</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.36</version>
        </dependency>

import com.alibaba.fastjson.JSONObject;
import com.ql.util.express.DefaultContext;
import com.ql.util.express.ExpressRunner;

public class Application {

    public static void main(String[] args) throws Exception {
        ExpressRunner runner = new ExpressRunner();
        DefaultContext<String, Object> context = new DefaultContext<String, Object>();
        context.put("a", 1);
        context.put("b", 2);
        context.put("c", 3);
        String express = "a + b * c";

        Object r = runner.execute(express, context, null, true, false);
        System.out.println(r);

        runner.addOperatorWithAlias("如果", "if", null);
        runner.addOperatorWithAlias("则", "then", null);
        runner.addOperatorWithAlias("否则", "else", null);

        express = "如果 (语文 + 数学 + 英语 > 270) 则 {return 1;} 否则 {return 0;}";
        DefaultContext<String, Object> context1 = new DefaultContext<String, Object>();
        Object execute = runner.execute(express, context1, null, false, false, null);
        System.out.println(execute);
        runner = new ExpressRunner();
        //runner.addOperatorWithAlias("结果", json,null);
        runner.addOperatorWithAlias("如果", "if", null);
        runner.addOperatorWithAlias("或", "||", null);
        runner.addOperatorWithAlias("且", "&&", null);
        runner.addOperatorWithAlias("等于", "==", null);
        runner.addOperatorWithAlias("大于", ">", null);
        runner.addOperatorWithAlias("小于", "<", null);
        runner.addOperatorWithAlias("则", "then", null);
        runner.addOperatorWithAlias("否则", "else", null);
        runner.addOperatorWithAlias("返回", "return", null);
        runner.addFunctionOfClassMethod("获取JSON中的值", Application.class.getName(), "getValue", new String[]{"String"}, null);

        express = "如果 (获取JSON中的值(\"code\") 等于 2 ) 则 {返回 true} 否则 {返回 false}";
        Object execute1 = runner.execute(express, context, null, true, false);
        System.out.println(execute1);
    }

    public static Object getValue(String name) {
        return JSONObject.parseObject(json).get(name);
    }

    private static final String json = "{\n" +
            "    \"code\": 1,\n" +
            "    \"message\": \"success\"\n" +
            "}";

}

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