java 使用js 引擎处理业务逻辑

一个比较简单的demo，就是基于java 内置的js 引擎，扩展业务逻辑代码，实现一个xml 解析的

项目结构

• 代码简单说明
  就是js 中使用了jackson xml 处理，同时获取xml 数组的第一个，转换为book 对象，方便业务处理
• pom.xml

 

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0"

         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

​

    <groupId>com.dalong</groupId>

    <artifactId>xmljs</artifactId>

    <version>1.0-SNAPSHOT</version>

    <properties>

        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

        <encoding>UTF-8</encoding>

        <java.version>1.8</java.version>

        <maven.compiler.source>1.8</maven.compiler.source>

        <maven.compiler.target>1.8</maven.compiler.target>

    </properties>

    <dependencies>

        <dependency>

            <groupId>com.fasterxml.jackson.dataformat</groupId>

            <artifactId>jackson-dataformat-xml</artifactId>

            <version>2.10.1</version>

        </dependency>

    </dependencies>

</project>

 

• 代码
  很简单，就是js 引擎，使用jackson xml 的处理方法，实现一个互调用

 

package com.dalong;

import jdk.nashorn.api.scripting.NashornScriptEngineFactory;

import javax.script.ScriptException;

import javax.script.SimpleBindings;

​

public class Application {

​

    public static void main(String[] args) throws ScriptException {

        String xmlcontent2 ="<bookstore>\n" +

                "<book category=\"COOKING\">\n" +

                "  <title lang=\"en\">Everyday Italian</title> \n" +

                "  <author>Giada De Laurentiis</author> \n" +

                "  <year>2005</year> \n" +

                "  <price>30.00</price> \n" +

                "</book>\n" +

                "<book category=\"CHILDREN\">\n" +

                "  <title lang=\"en\">Harry Potter</title> \n" +

                "  <author>J K. Rowling</author> \n" +

                "  <year>2005</year> \n" +

                "  <price>29.99</price> \n" +

                "</book>\n" +

                "<book category=\"WEB\">\n" +

                "  <title lang=\"en\">Learning XML</title> \n" +

                "  <author>Erik T. Ray</author> \n" +

                "  <year>2003</year> \n" +

                "  <price>39.95</price> \n" +

                "</book>\n" +

                "</bookstore>";

        // read xml array and then convert to list

         // 返回的实体，强制转换为 Book 对象

        String jsfunc2 = "function demo(xmlcontent) {\n" +

                "\tvar XmlMapper =  Java.type(\"com.fasterxml.jackson.dataformat.xml.XmlMapper\")\n" +

                "\tvar  myxmlmapper =new XmlMapper();\n" +

                "\tvar List =  Java.type(\"java.util.List\")\n" +

                "\tvar Book =  Java.type(\"com.dalong.Book\")\n" +

                "\tvar result = myxmlmapper.readValue(xmlcontent,List.class)\n" +

                "\treturn new Book(result[0].category,result[0].author,result[0].year,result[0].price)\n" +

                "}; demo(xml)";

        Book result = printXmlWithJs(jsfunc2,xmlcontent2);

        System.out.println(result.execute());

    }

    // result with jsonnode for better query ,also can convert to map

    public  static Book printXmlWithJs(String jsScript, String xmlContent) throws ScriptException {

        NashornScriptEngineFactory engine = new NashornScriptEngineFactory();

        SimpleBindings simpleBindings =new SimpleBindings();

        simpleBindings.putIfAbsent("xml",xmlContent);

        Object result =  engine.getScriptEngine("--language=es6").eval(jsScript,simpleBindings);

        if (result instanceof  Book){

            return (Book)result;

        }

        else {

            return  null;

        }

    }

}

 

Book.java

package com.dalong;

​

public class Book {

​

    private String category;

​

    public String getCategory() {

        return category;

    }

    public  Book(){

​

    }

​

    @Override

    public String toString() {

        return "Book{" +

                "category='" + category + '\'' +

                ", author='" + author + '\'' +

                ", year=" + year +

                ", price=" + price +

                '}';

    }

​

    public String execute(){

        return String.format("%s",this.toString());

    }

    public  Book(String  category,String author, int year,double price){

         this.author=author;

         this.category=category;

         this.year=year;

         this.price=price;

    }

​

    public void setCategory(String category) {

        this.category = category;

    }

​

    public String getAuthor() {

        return author;

    }

​

    public void setAuthor(String author) {

        this.author = author;

    }

​

    public int getYear() {

        return year;

    }

​

    public void setYear(int year) {

        this.year = year;

    }

​

    public double getPrice() {

        return price;

    }

​

    public void setPrice(double price) {

        this.price = price;

    }

​

    private String author;

    private int year;

    private double price;

}

• 运行效果

 

 

说明

实际如果需要使用我们可以集成spi 或者jar 包模式的进行扩展

参考资料

https://github.com/FasterXML/jackson-dataformat-xml