20110622

删除文件或文件夹
public static void deleteFile(File file) {
if (file.isDirectory()) {
File[] files = file.listFiles();
for (int i = 0; i < files.length; i++) {
File tempFile = files[i];
if (tempFile.isDirectory()) {
deleteFile(tempFile);
tempFile.delete();
} else {
tempFile.delete();
}
}
}
file.delete();
}
令记：
File file = new File("D:\\test\\3");
boolean b=file.mkdir();
boolean c=file.mkdirs();
mkdir(),mkdirs()区别当D:\\test不存在时，mkdir()不会创建文件夹3，而mkdirs()会创建包含test在内的文件夹。
============
通过在spring的xml配置文件里声明要对property进行操作的类，例如解压数据库的连接密码等作用。
<bean id="propertyConfigurer"
class="a.b.c.PropConfigurer">
<property name="locations">
<list>
<value>file:test/a.properties
</value>
</list>
</property>
</bean>

package a.b.c.purge;

import java.util.Properties;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer;


public class PropConfigurer extends PropertyPlaceholderConfigurer {

@Override
protected void processProperties(
ConfigurableListableBeanFactory beanFactory, Properties props)
throws BeansException {
String password = props.getProperty("db_password");
if (password != null) {
try {
props.setProperty("db_password", 解密(password));
} catch (Exception e) {
e.printStackTrace();
}
}
super.processProperties(beanFactory, props);
} 
============
使用spring的JDBC模板的一种方法：


PreparedStatementSetter pss = new PreparedStatementSetter() {

@Override
public void setValues(PreparedStatement pstm) throws SQLException {
pstm.setTimestamp(1, calcTimeStamp(getCrtRawPeriod()));
}
};
int cnt = jdbcTemplate.update(sqlString, pss);
===============
execute shell command from java :
public static void main(String[] args) throws Exception {

String cmd = "ipconfig";
Runtime run = Runtime.getRuntime();
Process pr = run.exec(cmd);
pr.waitFor();
BufferedReader buf = new BufferedReader(new InputStreamReader(pr.getInputStream()));
String line = "";
while ((line=buf.readLine())!=null) {
System.out.println(line);
}}
public static void main(String[] args) throws Exception {

String cmd = "ipconfig";
Runtime run = Runtime.getRuntime();
Process pr = run.exec(cmd);
pr.waitFor();
BufferedReader buf = new BufferedReader(new InputStreamReader(pr.getInputStream()));
String line = "";
while ((line=buf.readLine())!=null) {
System.out.println(line);
}}