我正在使用hibernate连接我的mysql数据库并执行事务.
我在整个应用程序中使用单个SessionFactory,并且我没有与数据库的其他连接,但是,我收到以下异常:
java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:3008)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3466)
... 21 common frames omitted
Wrapped by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 526 milliseconds ago. The last packet sent successfully to the server was 1 milliseconds ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3556)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3456)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3897) …您可以使用以下代码生成圆形渐变：
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<gradient
android:centerColor="#c1c1c1"
android:endColor="#4f4f4f"
android:gradientRadius="400"
android:startColor="#c1c1c1"
android:type="radial" >
</gradient>
</shape>
但是如何在 Android 中绘制椭圆渐变呢？即X和Y的半径不同？
我正在尝试使用 Jsoup 库抓取网页（此网页）。在执行简单的 GET 操作时，我收到以下异常：
javax.net.ssl|DEBUG|01|main|2018-12-24 15:41:06.431 EET|Utilities.java:73|the previous server name in SNI (type=host_name (0), value=www.kitapburada.com) was replaced with (type=host_name (0), value=www.kitapburada.com)
javax.net.ssl|DEBUG|01|main|2018-12-24 15:41:06.432 EET|HandshakeContext.java:290|Ignore unsupported cipher suite: TLS_AES_128_GCM_SHA256 for TLS12
javax.net.ssl|DEBUG|01|main|2018-12-24 15:41:06.432 EET|HandshakeContext.java:290|Ignore unsupported cipher suite: TLS_AES_256_GCM_SHA384 for TLS12
javax.net.ssl|DEBUG|01|main|2018-12-24 15:41:06.433 EET|HandshakeContext.java:290|Ignore unsupported cipher suite: TLS_AES_128_GCM_SHA256 for TLS11
javax.net.ssl|DEBUG|01|main|2018-12-24 15:41:06.433 EET|HandshakeContext.java:290|Ignore unsupported cipher suite: TLS_AES_256_GCM_SHA384 for TLS11
javax.net.ssl|DEBUG|01|main|2018-12-24 15:41:06.433 EET|HandshakeContext.java:290|Ignore unsupported cipher suite: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 for TLS11
javax.net.ssl|DEBUG|01|main|2018-12-24 15:41:06.433 EET|HandshakeContext.java:290|Ignore unsupported cipher suite: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 for TLS11
javax.net.ssl|DEBUG|01|main|2018-12-24 15:41:06.433 …我正在File.length()计算字数,我总是得到1个字节File.length().
这是我用来比较的片段:
File testFile = new File("testdir", "testfile.txt");
FileInputStream in = new FileInputStream(testFile );
byte[] buffer = new byte[1024];
int len = in.read(buffer);
int byteCount = len;
while (len != -1) {
len = in.read(buffer);
byteCount += len;
}
System.out.println("count: " + byteCount + ", file.length(): " +
testFile.length() + ", is_equal: "+(byteCount == testFile.length()));
而输出是 count: 15853294, file.length(): 15853295, is_equal: false
1字节来自哪里？是EOF？