Daihui Gu

Results 60 issues of Daihui Gu

``` public class StringSplitTest { @Test public void test() { String s = "aba"; // 很明显,这是2 assertEquals(2, s.split("b").length); s = "abab"; // 注意,这是2 assertEquals(2, s.split("b").length); s = "abab "; //...

[http://tomcat.apache.org/tomcat-7.0-doc/config/http.html](http://tomcat.apache.org/tomcat-7.0-doc/config/http.html) 示例如下: ``` ``` enableLookups 表示 `request.getRemoteHost()` 是否返回域名,默认false,直接返回ip,提高效率。 compression 及相关参数表示是否启用gzip压缩,及其最小压缩大小,压缩的类型。 URIEncoding 表示默认的URL编码。

[http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.3](http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.3) 在java编译器中,[ 表示一个数组,后面紧接一个字母表示数组类型。排除基本类型,其余都是L。如下: ``` [Z = boolean [B = byte [S = short [I = int [J = long [F = float [D = double [C = char [L =...

### 问题发现 1、监控服务器,发现负载中平均升高了一个,而其中的System CPU使用率一直维持在60左右。 2、查看TOP -H 发现其中一个线程的的CPU使用率一直是100,恰好完整占用一核(系统是4核) 3、用jstack导出堆栈,找到CPU高的这个线程堆栈信息如下: ``` java.lang.Thread.State: RUNNABLE at java.net.PlainSocketImpl.socketAvailable(Native Method) at java.net.AbstractPlainSocketImpl.available(AbstractPlainSocketImpl.java:478) - locked (a java.net.SocksSocketImpl) at java.net.SocketInputStream.available(SocketInputStream.java:245) at com.mysql.jdbc.util.ReadAheadInputStream.available(ReadAheadInputStream.java:232) at com.mysql.jdbc.MysqlIO.clearInputStream(MysqlIO.java:949) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2404) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2629)...

``` 69.147.76.173 flickr.com 69.147.76.173 www.flickr.com 206.190.57.60 m.flickr.com 206.190.57.61 secure.flickr.com 66.196.66.213 api.flickr.com 98.139.199.205 up.flickr.com ```

``` #!/usr/bin/expect set server [lindex $argv 0]; set timeout 3 spawn ssh daihui.gu@$server expect "passphrase" send "mypassword\r" interact ```

Linux

所用单片机均是 51,参加学校智能车大赛的代码。分两个代码: ### 代码一 ``` #include "reg52.h" #define uint unsigned int #define uchar unsigned char uchar num[] ={0x03,0x9f,0x25,0x0d,0x99,0x49,0x41,0x1f,0x01,0x09}; sbit p1_0=P1^0; //D2,低有效 sbit p1_1=P1^1; //D3,低有效 sbit p1_2=P1^2; // sbit p1_3=P1^3; //...

``` public static void main(String[] args) throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException { Class cache = Integer.class.getDeclaredClasses ()[0]; Field c = cache.getDeclaredField ("cache"); c.setAccessible (true); Integer[] array = (Integer[]) c.get (cache);...

tomcat 自带验证,可设置指定路径需要验证,/*表示项目所有路径,在web.xml下加上以下配置就行了,简单方便。另需在conf/tomcat-user.xml中添加用户名密码。 ``` Security Constraint RES /* tomcat BASIC My RES ```

Other

``` package test; import java.util.HashMap; import java.util.Map; public class Sizeof { private static final Runtime s_runtime = Runtime.getRuntime(); public static void main(String[] args) throws Exception { // Warm up all...