个人中心
文章发布
退出
作者热门文章
- android - 多次调用 OnPrimaryClipChangedListener
- android - 无法更新 RecyclerView 中的 TextView 字段
- android.database.CursorIndexOutOfBoundsException : Index 0 requested, 光标大小为 0
- android - 使用 AppCompat 时，我们是否需要明确指定其 UI 组件(Spinner、EditText)颜色
38
4
我正在尝试连接 SSL 站点 https://link.bollore-logistics.com通过使用 Java 6 和 HTMLUnit，我使用 Bouncy CaSTLe 添加了更多受支持的密码。但是，我仍然收到握手失败。由于生产限制，我无法升级 Java 版本。请帮忙
配置代码:
HttpsURLConnection.setDefaultHostnameVerifier(new HostnameVerifier() {
public boolean verify(String hostname, SSLSession session) {
return true;
}
});
if (Security.getProvider("BC") == null){
logger.info("Bouncy Castle provider is NOT available");
}
else{
logger.info("Bouncy Castle provider is available");
}
Provider provider = new BouncyCastleProvider();
Security.addProvider(provider);
SSLContext context = SSLContext.getInstance("SSL");
context.init(null, new X509TrustManager[]{new X509TrustManager() {
@Override
public void checkClientTrusted(X509Certificate[] arg0, String arg1) throws CertificateException {
}
@Override
public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
}
@Override
public X509Certificate[] getAcceptedIssuers() {
return null;
}
}}, new SecureRandom());
String[] scs = context.getSocketFactory().getSupportedCipherSuites();
Arrays.sort(scs);
for(String s : scs) {
System.out.println(s);
}
HttpsURLConnection.setDefaultSSLSocketFactory(context.getSocketFactory());
// Create all-trusting host name verifier
HostnameVerifier allHostsValid = new HostnameVerifier() {
public boolean verify(String hostname, SSLSession session) {
return true;
}
};
HttpsURLConnection.setDefaultHostnameVerifier(allHostsValid);
建立连接的代码(HTMLUnit):
WebClient webClient = new WebClient(BrowserVersion.CHROME);
webClient.getOptions().setUseInsecureSSL(true);
webClient.getOptions().setRedirectEnabled(true);
webClient.getOptions().setThrowExceptionOnScriptError(false);
webClient.getOptions().setCssEnabled(false);
webClient.getOptions().setJavaScriptEnabled(true);
webClient.getPage(url);
错误日志如下:
2017-12-06 11:27:40 DEBUG WebClient:325 - Get page for window named '', using WebRequest[<url="http://link.bollore-logistics.com/Contact/SmartSearch/77707575", GET, EncodingType[name=application/x-www-form-urlencoded], [], {Accept-Encoding=gzip, deflate, Accept=*/*}, null>]
2017-12-06 11:27:40 DEBUG WebClient:1259 - Load response for GET http://link.bollore-logistics.com/Contact/SmartSearch/77707575
trigger seeding of SecureRandom
done seeding SecureRandom
2017-12-06 11:27:40 DEBUG RequestAddCookies:122 - CookieSpec selected: mine
2017-12-06 11:27:40 DEBUG RequestAuthCache:76 - Auth cache not set in the context
2017-12-06 11:27:40 DEBUG PoolingHttpClientConnectionManager:249 - Connection request: [route: {}->http://link.bollore-logistics.com:80][total kept alive: 0; route allocated: 0 of 6; total allocated: 0 of 20]
2017-12-06 11:27:40 DEBUG PoolingHttpClientConnectionManager:282 - Connection leased: [id: 0][route: {}->http://link.bollore-logistics.com:80][total kept alive: 0; route allocated: 1 of 6; total allocated: 1 of 20]
2017-12-06 11:27:40 DEBUG MainClientExec:234 - Opening connection {}->http://link.bollore-logistics.com:80
2017-12-06 11:27:40 DEBUG DefaultHttpClientConnectionOperator:131 - Connecting to link.bollore-logistics.com/195.101.158.66:80
2017-12-06 11:27:40 DEBUG DefaultHttpClientConnectionOperator:138 - Connection established 192.168.171.168:52556<->195.101.158.66:80
2017-12-06 11:27:40 DEBUG MainClientExec:255 - Executing request GET /Contact/SmartSearch/77707575 HTTP/1.1
2017-12-06 11:27:40 DEBUG MainClientExec:260 - Target auth state: UNCHALLENGED
2017-12-06 11:27:40 DEBUG MainClientExec:266 - Proxy auth state: UNCHALLENGED
2017-12-06 11:27:40 DEBUG headers:124 - http-outgoing-0 >> GET /Contact/SmartSearch/77707575 HTTP/1.1
2017-12-06 11:27:40 DEBUG headers:127 - http-outgoing-0 >> Host: link.bollore-logistics.com
2017-12-06 11:27:40 DEBUG headers:127 - http-outgoing-0 >> User-Agent: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.63 Safari/537.36
2017-12-06 11:27:40 DEBUG headers:127 - http-outgoing-0 >> Accept-Language: en-US
2017-12-06 11:27:40 DEBUG headers:127 - http-outgoing-0 >> Accept-Encoding: gzip, deflate
2017-12-06 11:27:40 DEBUG headers:127 - http-outgoing-0 >> Accept: */*
2017-12-06 11:27:40 DEBUG headers:127 - http-outgoing-0 >> Connection: Keep-Alive
2017-12-06 11:27:40 DEBUG wire:72 - http-outgoing-0 >> "GET /Contact/SmartSearch/77707575 HTTP/1.1[\r][\n]"
2017-12-06 11:27:40 DEBUG wire:72 - http-outgoing-0 >> "Host: link.bollore-logistics.com[\r][\n]"
2017-12-06 11:27:40 DEBUG wire:72 - http-outgoing-0 >> "User-Agent: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.63 Safari/537.36[\r][\n]"
2017-12-06 11:27:40 DEBUG wire:72 - http-outgoing-0 >> "Accept-Language: en-US[\r][\n]"
2017-12-06 11:27:40 DEBUG wire:72 - http-outgoing-0 >> "Accept-Encoding: gzip, deflate[\r][\n]"
2017-12-06 11:27:40 DEBUG wire:72 - http-outgoing-0 >> "Accept: */*[\r][\n]"
2017-12-06 11:27:40 DEBUG wire:72 - http-outgoing-0 >> "Connection: Keep-Alive[\r][\n]"
2017-12-06 11:27:40 DEBUG wire:72 - http-outgoing-0 >> "[\r][\n]"
2017-12-06 11:27:41 DEBUG wire:72 - http-outgoing-0 << "HTTP/1.0 302 Found[\r][\n]"
2017-12-06 11:27:41 DEBUG wire:72 - http-outgoing-0 << "Location: https://link.bollore-logistics.com/Contact/SmartSearch/77707575[\r][\n]"
2017-12-06 11:27:41 DEBUG wire:72 - http-outgoing-0 << "Server: BigIP[\r][\n]"
2017-12-06 11:27:41 DEBUG wire:72 - http-outgoing-0 << "Connection: Keep-Alive[\r][\n]"
2017-12-06 11:27:41 DEBUG wire:72 - http-outgoing-0 << "Content-Length: 0[\r][\n]"
2017-12-06 11:27:41 DEBUG wire:72 - http-outgoing-0 << "[\r][\n]"
2017-12-06 11:27:41 DEBUG headers:113 - http-outgoing-0 << HTTP/1.0 302 Found
2017-12-06 11:27:41 DEBUG headers:116 - http-outgoing-0 << Location: https://link.bollore-logistics.com/Contact/SmartSearch/77707575
2017-12-06 11:27:41 DEBUG headers:116 - http-outgoing-0 << Server: BigIP
2017-12-06 11:27:41 DEBUG headers:116 - http-outgoing-0 << Connection: Keep-Alive
2017-12-06 11:27:41 DEBUG headers:116 - http-outgoing-0 << Content-Length: 0
2017-12-06 11:27:41 DEBUG MainClientExec:284 - Connection can be kept alive indefinitely
2017-12-06 11:27:41 DEBUG PoolingHttpClientConnectionManager:314 - Connection [id: 0][route: {}->http://link.bollore-logistics.com:80] can be kept alive indefinitely
2017-12-06 11:27:41 DEBUG PoolingHttpClientConnectionManager:320 - Connection released: [id: 0][route: {}->http://link.bollore-logistics.com:80][total kept alive: 1; route allocated: 1 of 6; total allocated: 1 of 20]
2017-12-06 11:27:41 DEBUG WebClient:1349 - Got a redirect status code [302] new location = [https://link.bollore-logistics.com/Contact/SmartSearch/77707575]
2017-12-06 11:27:41 DEBUG WebClient:1259 - Load response for GET https://link.bollore-logistics.com/Contact/SmartSearch/77707575
2017-12-06 11:27:41 DEBUG RequestAddCookies:122 - CookieSpec selected: mine
2017-12-06 11:27:41 DEBUG RequestAuthCache:76 - Auth cache not set in the context
2017-12-06 11:27:41 DEBUG PoolingHttpClientConnectionManager:249 - Connection request: [route: {s}->https://link.bollore-logistics.com:443][total kept alive: 1; route allocated: 0 of 6; total allocated: 1 of 20]
2017-12-06 11:27:41 DEBUG PoolingHttpClientConnectionManager:282 - Connection leased: [id: 1][route: {s}->https://link.bollore-logistics.com:443][total kept alive: 1; route allocated: 1 of 6; total allocated: 2 of 20]
2017-12-06 11:27:41 DEBUG MainClientExec:234 - Opening connection {s}->https://link.bollore-logistics.com:443
2017-12-06 11:27:41 DEBUG DefaultHttpClientConnectionOperator:131 - Connecting to link.bollore-logistics.com/195.101.158.66:443
2017-12-06 11:27:41 DEBUG HtmlUnitSSLConnectionSocketFactory:335 - Connecting socket to link.bollore-logistics.com/195.101.158.66:443 with timeout 90000
2017-12-06 11:27:41 DEBUG HtmlUnitSSLConnectionSocketFactory:388 - Enabled protocols: [TLSv1]
2017-12-06 11:27:41 DEBUG HtmlUnitSSLConnectionSocketFactory:389 - Enabled cipher suites:[SSL_RSA_WITH_RC4_128_MD5, SSL_RSA_WITH_RC4_128_SHA, TLS_RSA_WITH_AES_128_CBC_SHA, TLS_ECDH_ECDSA_WITH_RC4_128_SHA, TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDH_RSA_WITH_RC4_128_SHA, TLS_ECDH_RSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, TLS_DHE_RSA_WITH_AES_128_CBC_SHA, TLS_DHE_DSS_WITH_AES_128_CBC_SHA, SSL_RSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA, SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA, SSL_RSA_WITH_DES_CBC_SHA, SSL_DHE_RSA_WITH_DES_CBC_SHA, SSL_DHE_DSS_WITH_DES_CBC_SHA, SSL_RSA_EXPORT_WITH_RC4_40_MD5, SSL_RSA_EXPORT_WITH_DES40_CBC_SHA, SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA, SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA]
2017-12-06 11:27:41 DEBUG HtmlUnitSSLConnectionSocketFactory:393 - Starting handshake
%% No cached client session
*** ClientHello, TLSv1
RandomCookie: GMT: 1512530605 bytes = { 147, 117, 177, 152, 172, 87, 109, 103, 219, 130, 24, 140, 216, 108, 154, 3, 162, 211, 205, 89, 29, 221, 91, 103, 85, 39, 206, 187 }
Session ID: {}
Cipher Suites: [SSL_RSA_WITH_RC4_128_MD5, SSL_RSA_WITH_RC4_128_SHA, TLS_RSA_WITH_AES_128_CBC_SHA, TLS_ECDH_ECDSA_WITH_RC4_128_SHA, TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDH_RSA_WITH_RC4_128_SHA, TLS_ECDH_RSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, TLS_DHE_RSA_WITH_AES_128_CBC_SHA, TLS_DHE_DSS_WITH_AES_128_CBC_SHA, SSL_RSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA, SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA, SSL_RSA_WITH_DES_CBC_SHA, SSL_DHE_RSA_WITH_DES_CBC_SHA, SSL_DHE_DSS_WITH_DES_CBC_SHA, SSL_RSA_EXPORT_WITH_RC4_40_MD5, SSL_RSA_EXPORT_WITH_DES40_CBC_SHA, SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA, SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA]
Compression Methods: { 0 }
Extension elliptic_curves, curve names: {secp256r1, sect163k1, sect163r2, secp192r1, secp224r1, sect233k1, sect233r1, sect283k1, sect283r1, secp384r1, sect409k1, sect409r1, secp521r1, sect571k1, sect571r1, secp160k1, secp160r1, secp160r2, sect163r1, secp192k1, sect193r1, sect193r2, secp224k1, sect239k1, secp256k1}
Extension ec_point_formats, formats: [uncompressed]
***
[write] MD5 and SHA1 hashes: len = 161
0000: 01 00 00 9D 03 01 5A 27 63 AD 93 75 B1 98 AC 57 ......Z'c..u...W
0010: 6D 67 DB 82 18 8C D8 6C 9A 03 A2 D3 CD 59 1D DD mg.....l.....Y..
0020: 5B 67 55 27 CE BB 00 00 36 00 04 00 05 00 2F C0 [gU'....6...../.
0030: 02 C0 04 C0 0C C0 0E C0 07 C0 09 C0 11 C0 13 00 ................
0040: 33 00 32 00 0A C0 03 C0 0D C0 08 C0 12 00 16 00 3.2.............
0050: 13 00 09 00 15 00 12 00 03 00 08 00 14 00 11 01 ................
0060: 00 00 3E 00 0A 00 34 00 32 00 17 00 01 00 03 00 ..>...4.2.......
0070: 13 00 15 00 06 00 07 00 09 00 0A 00 18 00 0B 00 ................
0080: 0C 00 19 00 0D 00 0E 00 0F 00 10 00 11 00 02 00 ................
0090: 12 00 04 00 05 00 14 00 08 00 16 00 0B 00 02 01 ................
00A0: 00 .
http-bio-8080-exec-3, WRITE: TLSv1 Handshake, length = 161
[Raw write]: length = 166
0000: 16 03 01 00 A1 01 00 00 9D 03 01 5A 27 63 AD 93 ...........Z'c..
0010: 75 B1 98 AC 57 6D 67 DB 82 18 8C D8 6C 9A 03 A2 u...Wmg.....l...
0020: D3 CD 59 1D DD 5B 67 55 27 CE BB 00 00 36 00 04 ..Y..[gU'....6..
0030: 00 05 00 2F C0 02 C0 04 C0 0C C0 0E C0 07 C0 09 .../............
0040: C0 11 C0 13 00 33 00 32 00 0A C0 03 C0 0D C0 08 .....3.2........
0050: C0 12 00 16 00 13 00 09 00 15 00 12 00 03 00 08 ................
0060: 00 14 00 11 01 00 00 3E 00 0A 00 34 00 32 00 17 .......>...4.2..
0070: 00 01 00 03 00 13 00 15 00 06 00 07 00 09 00 0A ................
0080: 00 18 00 0B 00 0C 00 19 00 0D 00 0E 00 0F 00 10 ................
0090: 00 11 00 02 00 12 00 04 00 05 00 14 00 08 00 16 ................
00A0: 00 0B 00 02 01 00 ......
[Raw read]: length = 5
0000: 15 03 01 00 02 .....
[Raw read]: length = 2
0000: 02 28 .(
http-bio-8080-exec-3, READ: TLSv1 Alert, length = 2
http-bio-8080-exec-3, RECV TLSv1 ALERT: fatal, handshake_failure
http-bio-8080-exec-3, called closeSocket()
http-bio-8080-exec-3, handling exception: javax.net.ssl.SSLHandshakeException: Received fatal alert: handshake_failure
2017-12-06 11:27:41 DEBUG DefaultManagedHttpClientConnection:87 - http-outgoing-1: Shutdown connection
2017-12-06 11:27:41 DEBUG MainClientExec:128 - Connection discarded
2017-12-06 11:27:41 DEBUG DefaultManagedHttpClientConnection:79 - http-outgoing-1: Close connection
2017-12-06 11:27:41 DEBUG PoolingHttpClientConnectionManager:320 - Connection released: [id: 1][route: {s}->https://link.bollore-logistics.com:443][total kept alive: 1; route allocated: 0 of 6; total allocated: 1 of 20]
javax.net.ssl.SSLHandshakeException: Received fatal alert: handshake_failure
at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:174)
at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:136)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.recvAlert(SSLSocketImpl.java:1694)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:939)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1120)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1147)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1131)
at org.apache.http.conn.ssl.SSLConnectionSocketFactory.createLayeredSocket(SSLConnectionSocketFactory.java:394)
at org.apache.http.conn.ssl.SSLConnectionSocketFactory.connectSocket(SSLConnectionSocketFactory.java:353)
at com.gargoylesoftware.htmlunit.HtmlUnitSSLConnectionSocketFactory.connectSocket(HtmlUnitSSLConnectionSocketFactory.java:155)
at org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.java:134)
at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.connect(PoolingHttpClientConnectionManager.java:353)
at org.apache.http.impl.execchain.MainClientExec.establishRoute(MainClientExec.java:380)
at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:236)
at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:184)
at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:88)
at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:71)
at com.gargoylesoftware.htmlunit.HttpWebConnection.getResponse(HttpWebConnection.java:178)
at com.gargoylesoftware.htmlunit.WebClient.loadWebResponseFromWebConnection(WebClient.java:1313)
at com.gargoylesoftware.htmlunit.WebClient.loadWebResponseFromWebConnection(WebClient.java:1371)
at com.gargoylesoftware.htmlunit.WebClient.loadWebResponse(WebClient.java:1230)
at com.gargoylesoftware.htmlunit.WebClient.getPage(WebClient.java:338)
at com.gargoylesoftware.htmlunit.WebClient.getPage(WebClient.java:407)
at com.gargoylesoftware.htmlunit.WebClient.getPage(WebClient.java:392)
at com.grabber.Grabber.accessWebpage(Grabber.java:204)
at com.grabber.Grabber.doGet(Grabber.java:53)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:506)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:962)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1087)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:619)
最佳答案
我有一个类似的问题(但在那种情况下没有使用 HtmlUnit。我直接使用了 org.apache.http.impl.client.CloseableHttpClient)。
直到 java 7 握手似乎有问题(在 java 8 中不再有问题)。如果您尝试访问提供“TLSv1.2”的服务器，您可能会收到您报告的错误。
如果您的情况下安全性不是什么大问题，您可以尝试强制使用 TLSv1.1(只要您尚未切换到 java 8)。这应该可以这样:
WebClientOptions webClientOptions= new WebClientOptions();
webClientOptions.setSSLClientProtocols(new String[]{"TLSv1.1"});
SSLConnectionSocketFactory.buildSSLSocketFactory(webClientOptions);
关于使用 Java 6、HTMLUnit 和 Bouncy CaSTLe 的 TLSv1 SSL 握手失败，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47666408/
38
4
0
我正在编写一个具有以下签名的 Java 方法。 void Logger(Method method, Object[] args); 如果一个方法(例如 ABC() )调用此方法 Logger，它应该
我是 Java 新手。 我的问题是我的 Java 程序找不到我试图用作的图像文件一个 JButton。 (目前这段代码什么也没做，因为我只是得到了想要的外观第一的)。这是我的主课 代码: packag
好的，今天我在接受采访，我已经编写 Java 代码多年了。采访中说“Java 垃圾收集是一个棘手的问题，我有几个 friend 一直在努力弄清楚。你在这方面做得怎么样？”。她是想骗我吗？还是我的一生都
我的 friend 给了我一个谜语让我解开。它是这样的: There are 100 people. Each one of them, in his turn, does the following
如果我将使用 Java 5 代码的应用程序编译成字节码，生成的 .class 文件是否能够在 Java 1.4 下运行？ 如果后者可以工作并且我正在尝试在我的 Java 1.4 应用程序中使用 Jav
有关于why Java doesn't support unsigned types的问题以及一些关于处理无符号类型的问题。我做了一些搜索，似乎 Scala 也不支持无符号数据类型。限制是Java和S
我只是想知道在一个 java 版本中生成的字节码是否可以在其他 java 版本上运行 最佳答案 通常，字节码无需修改即可在 较新 版本的 Java 上运行。它不会在旧版本上运行，除非您使用特殊参数 (
我有一个关于在命令提示符下执行 java 程序的基本问题。 在某些机器上我们需要指定 -cp 。 (类路径)同时执行java程序 (test为java文件名与.class文件存在于同一目录下) jav
我已经阅读 StackOverflow 有一段时间了，现在我才鼓起勇气提出问题。我今年 20 岁，目前在我的家乡(罗马尼亚克卢日-纳波卡)就读 IT 大学。足以介绍:D。 基本上，我有一家提供簿记应用
我有 public JSONObject parseXML(String xml) { JSONObject jsonObject = XML.toJSONObject(xml); r
我已经在 Java 中实现了带有动态类型的简单解释语言。不幸的是我遇到了以下问题。测试时如下代码: def main() { def ks = Map[[1, 2]].keySet()
一直提示输入 1 到 10 的数字 - 结果应将 st、rd、th 和 nd 添加到数字中。编写一个程序，提示用户输入 1 到 10 之间的任意整数，然后以序数形式显示该整数并附加后缀。 public
我有这个 DownloadFile.java 并按预期下载该文件: import java.io.*; import java.net.URL; public class DownloadFile {
我想在 GUI 上添加延迟。我放置了 2 个 for 循环，然后重新绘制了一个标签，但这 2 个 for 循环一个接一个地执行，并且标签被重新绘制到最后一个。 我能做什么？ for(int i=0;
我正在对对象 Student 的列表项进行一些测试，但是我更喜欢在 java 类对象中创建硬编码列表，然后从那里提取数据，而不是连接到数据库并在结果集中选择记录。然而，自从我这样做以来已经很长时间了，
我知道对象创建分为三个部分: 声明 实例化 初始化 classA{} classB extends classA{} classA obj = new classB(1,1); 实例化 它必须使用
我有兴趣使用 GPRS 构建车辆跟踪系统。但是，我有一些问题要问以前做过此操作的人: GPRS 是最好的技术吗？人们意识到任何问题吗？ 我计划使用 Java/Java EE - 有更好的技术吗？ 如果
我可以通过递归方法反转数组，例如:数组={1,2,3,4,5} 数组结果={5,4,3,2,1}但我的结果是相同的数组，我不知道为什么，请帮助我。 public class Recursion { p
有这样的标准方式吗？ 包括 Java源代码-测试代码- Ant 或 Maven联合单元持续集成(可能是巡航控制)ClearCase 版本控制工具部署到应用服务器 最后我希望有一个自动构建和集成环境。
我什至不知道这是否可能，我非常怀疑它是否可能，但如果可以，您能告诉我怎么做吗？我只是想知道如何从打印机打印一些文本。 有什么想法吗？ 最佳答案 这里有更简单的事情。 import javax.swin
我是一名优秀的程序员,十分优秀！