java 使用js 引擎處理業務邏輯
阿新 • • 發佈：2020-10-27
一個比較簡單的demo，就是基於java 內建的js 引擎，擴充套件業務邏輯程式碼，實現一個xml 解析的
專案結構
- 程式碼簡單說明
就是js 中使用了jackson xml 處理，同時獲取xml 陣列的第一個，轉換為book 物件，方便業務處理 - 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>
- 程式碼
很簡單，就是js 引擎，使用jackson xml 的處理方法，實現一個互呼叫
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
// 返回的實體，強制轉換為 Book 物件
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;
}
- 執行效果
說明
實際如果需要使用我們可以整合spi 或者jar 包模式的進行擴充套件