java - 访问 .jar API 函数 - 错误 : Cannot make a static reference to the non-static method

Question

这个问题已经有答案了:

Calling Non-Static Method In Static Method In Java [duplicate] (14 个回答)

已关闭 9 年前。

我正在开发一个 PhoneGap 应用程序，使用 Javascript 与 Java 进行通信。我正在尝试访问名为 A100_AL1001-23_AndroidLibrary.jar 的 JAR 文件中名为 RcpApi2 的类，但是当我尝试访问其中的函数时，出现此错误:

Cannot make a static reference to the non-static method startReadTagsWithRssi(int, int,  int) from the type RcpApi2

当我尝试访问这些方法时发生错误:

• RcpApi2.open();
• RcpApi2.isopen;
• RcpApi2.startReadTagsWithRssi(...);

有谁知道为什么会发生这种情况/如何解决这个问题？

项目目录:

Java 代码:

import com.phychips.rcp.*;

public class HelloPlugin extends Plugin implements iRcpEvent2 {

public static final String KEY_ENCODING = "my_encoding";
public static final String KEY_SAVELOG = "my_saveLog";
public static final String NATIVE_ACTION_STRING="nativeAction"; 
public static final String SUCCESS_PARAMETER="success";
...

    public PluginResult execute(String action, JSONArray dataArray, String callbackId) {

     if (NATIVE_ACTION_STRING.equals(action)) {

         String resultType = null;
         try {
             resultType = dataArray.getString(0);    
         }
         catch (Exception ex) {
             Log.d("HelloPlugin", ex.toString());
         }

         if (resultType.equals(SUCCESS_PARAMETER)) {

             RcpApi2.getInstance().setOnRcpEventListener(this);

            try {
                RcpApi2.open();             


            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            if (RcpApi2.isOpen)
            {           
                try {       
                    boolean k = RcpApi2.startReadTagsWithRssi(maxTags, maxTime, repeatCycle);
                    return new PluginResult(PluginResult.Status.OK, "Yay, Success!!!");

                } catch (RcpException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }           
            }

Jar 文件代码:

public class RcpApi2 extends BroadcastReceiver {

    private boolean isOpen = false;

    public boolean open() throws Exception {
        init(mIoType);
        readerIo.open();
        isOpen = true;
    }

    public boolean isOpen() {
        return this.isOpen;
    }

    public boolean startReadTagsWithRssi(int maxTags, int maxTime, int repeatCycle) {
        RcpPacket rcpPacket = RcpPacket.getInstance();
        if (!this.mIRcp.startReadTagsWithRssi(rcpPacket, maxTags, maxTime, repeatCycle)) {
            return false;
        }
        boolean ret = true;
        ...
        return ret;
     }

}

Answer 1

RcpApi2中的那些方法不是静态的，您必须使用从RcpApi2.getInstance()返回的实例

例如，更改此:

RcpApi2.getInstance().setOnRcpEventListener(this);

try {
    RcpApi2.open();      

} catch (Exception e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

对此:

RCPApi2 rcpAPI = RCPApi2.getInstance();
rcpAPI.setOnRcpEventListener(this);

try {
    rcpAPI.open();             


} catch (Exception e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

并随着代码的进行继续使用 rcpAPI 实例。