Question

我是javascript和java编程的新手。我有一个带有函数updateInfo（）的.java文件。我想在我的.js文件中调用该函数。我怎样才能做到这一点？请帮忙。感谢!!!

Answer 1

是的，你可以，但不能直接。

一种选择是使用Apache CXF或Jersey等JAX-RS实现。一旦创建了映射到Java文件中的方法的RESTful Web服务，就可以使用JavaScript进行AJAX调用。因此，您当然可以通过REST以RESTful Web服务的形式调用Java方法。

Answer 2

您不能直接从JavaScript调用java方法。等于java代码是否已编译。

Answer 3

要使用JavaScript绑定Java代码，您必须先创建Applet。只有在之后，有几种技术可以调用JavaScript from Applet，反之亦然

Answer 4

首先确保将java编译为jar（并扩展applet / japplet）

您可以使用netscape.javascript.*

调用javascript函数

示例HTML

<head>
<title>Data Summary Applet Page - Java to JavaScript LiveConnect</title>
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252"/>
<script language="javascript">
    var userName = "";

    // returns number
    function getAge() { 
        return 25;
    }
    // returns an object
    function address() { 
        this.street = "1 Example Lane";
        this.city = "Santa Clara";
        this.state = "CA";
    }
    // returns an array
    function getPhoneNums() { 
        return ["408-555-0100", "408-555-0102"];
    } 
    function writeSummary(summary) {
        summaryElem =
            document.getElementById("summary");
        summaryElem.innerHTML = summary;
    }
    </script>

    <!-- ... -->      
</head>
<body>
    <script src =
      "http://www.java.com/js/deployJava.js"></script>
    <script> 
        <!-- ... -->
        deployJava.runApplet(attributes, parameters, '1.6'); 
    </script>          
    <!-- ... -->
    <p id="summary"/>  // this HTML element contains
                             // the summary 
    <!-- ... -->
</body>

示例java实现：

package javatojs;

import java.applet.Applet;
import netscape.javascript.*; // add plugin.jar to classpath during compilation

public class DataSummaryApplet extends Applet {
    public void start() {
        try {
            JSObject window = JSObject.getWindow(this);

            String userName = "John Doe";

            // set JavaScript variable
            window.setMember("userName", userName);

            // invoke JavaScript function
            Number age = (Number) window.eval("getAge()");

            // get a JavaScript object and retrieve its contents
            JSObject address = (JSObject) window.eval("new address();");
            String addressStr = (String) address.getMember("street") + ", " +
                    (String) address.getMember("city") + ", " +
                    (String) address.getMember("state");

            // get an array from JavaScript and retrieve its contents
            JSObject phoneNums = (JSObject) window.eval("getPhoneNums()");
            String phoneNumStr = (String) phoneNums.getSlot(0) + ", " +
                    (String) phoneNums.getSlot(1);

            // dynamically change HTML in page; write data summary
            String summary = userName + " : " + age + " : " +
                    addressStr + " : " + phoneNumStr;
            window.call("writeSummary", new Object[] {summary})   ;
        } catch (JSException jse) {
            jse.printStackTrace();
        }
    }
}

More information about invoking javascript from java

More information about invoking java methods from javascript

从.js文件上的.java文件调用函数

4 个答案: