如何解决线程“main”中的异常java.lang.NoSuchFieldError：INSTANCE？

Question

我正在尝试使用Selenium网络驱动程序上传文件。以上错误收到。我知道代码还可以。大多数帖子都说这是因为“依赖”。我该如何解决？我检查了没有相同名称的jar文件。这里我展示了我的jar文件的一些屏幕截图。我该如何解决这个依赖性问题？

Java代码：

    import java.io.File;
    import java.io.IOException;
    import org.openqa.selenium.By;
    import org.openqa.selenium.WebDriver;
    import org.openqa.selenium.WebElement;
    import org.openqa.selenium.firefox.FirefoxDriver;
    import org.openqa.selenium.remote.CapabilityType;
    import org.openqa.selenium.remote.DesiredCapabilities;

    public class FusekiStart {

    public static void main(String[] args) {

        /* Selenium config  */
        String PROXY = "localhost:3030";

        org.openqa.selenium.Proxy proxy = new org.openqa.selenium.Proxy();
        proxy.setHttpProxy(PROXY)
             .setFtpProxy(PROXY)
             .setSslProxy(PROXY);
        DesiredCapabilities cap = new DesiredCapabilities();
        cap.setCapability(CapabilityType.PROXY, proxy);
        WebDriver driver = new FirefoxDriver(cap);
        driver.get("http://localhost:3030/control-panel.tpl");
        driver.findElement(By.xpath("//input[@value='Select']")).click();
                           driver.findElement(By.xpath("//input[@type='file']")).sendKeys("C:\\Users\\user1\\Desktop\\Ontology.owl"); 
        driver.findElement(By.xpath("//input[@value='Upload']")).click(); 

}

}

错误讯息：

    Exception in thread "main" java.lang.NoSuchFieldError: INSTANCE
    at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.<init>      (DefaultHttpRequestWriterFactory.java:52)
at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.<init>(DefaultHttpRequestWriterFactory.java:56)
at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.<clinit>(DefaultHttpRequestWriterFactory.java:46)
at org.apache.http.impl.conn.ManagedHttpClientConnectionFactory.<init>(ManagedHttpClientConnectionFactory.java:72)
at org.apache.http.impl.conn.ManagedHttpClientConnectionFactory.<init>(ManagedHttpClientConnectionFactory.java:84)
at org.apache.http.impl.conn.ManagedHttpClientConnectionFactory.<clinit>(ManagedHttpClientConnectionFactory.java:59)
at org.apache.http.impl.conn.PoolingHttpClientConnectionManager$InternalConnectionFactory.<init>(PoolingHttpClientConnectionManager.java:487)
at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.<init>(PoolingHttpClientConnectionManager.java:147)
at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.<init>(PoolingHttpClientConnectionManager.java:136)
at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.<init>(PoolingHttpClientConnectionManager.java:112)
at org.openqa.selenium.remote.internal.HttpClientFactory.getClientConnectionManager(HttpClientFactory.java:68)
at org.openqa.selenium.remote.internal.HttpClientFactory.<init>(HttpClientFactory.java:55)
at org.openqa.selenium.remote.HttpCommandExecutor.<init>(HttpCommandExecutor.java:99)
at org.openqa.selenium.remote.HttpCommandExecutor.<init>(HttpCommandExecutor.java:82)
at org.openqa.selenium.firefox.internal.NewProfileExtensionConnection.start(NewProfileExtensionConnection.java:93)
at org.openqa.selenium.firefox.FirefoxDriver.startClient(FirefoxDriver.java:246)
at org.openqa.selenium.remote.RemoteWebDriver.<init>(RemoteWebDriver.java:114)
at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:193)
at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:186)
at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:104)
at uom.brts.statisticalmt.FusekiStart.main(FusekiStart.java:39)

Answer 1

检查此链接： Source Code at Grep

您缺少org.apache.http.message包中的BasicLineFormatter类。

Answer 2

我会说这不会解决您的问题，但是您可以通过包含一个httpcore 4.2.2 jar文件来查看您当前正在使用的文件。您是否可以尝试从Link获取更高的值并将其替换为当前的httpcore 4.2.2，看看它有什么不同？

Answer 3

我遇到了同样的问题。经过大量调试后，我发现存在CLASSPATH冲突。项目中已存在的jar文件

httpclient-osgi-4.2.1.jar

与selenium jar文件冲突。对我来说幸运的是，项目中不再需要httpclient-osgi-4.2.1.jar文件，因此我可以安全地删除它。之后问题就消失了。

错误信息很可悲。它无论如何都无助于指出真正的问题。