if(!file.exists()){ if(!file.getParentFile().exists()) file.getParentFile().mkdirs(); file.mkdirs(); } } 3、.tar.gz文件可以看做先用tar打包,再使用gz进行压缩。使用org.apache.tools.tar.TarEntry; org.apache.tools.tar.TarInputStream 和 org.apache.tools.tar.TarOutputStream 需要导入pom文件...
If the specified path includes a file name and if that file already exists, the JVM creates a new file by appending the date and time stamp to the specified file name. globalbuffersize=size Specifies the total amount of primary memory (in bytes) used for data retention. Append k or K,...
*/ public HandleProperties(HttpSession session,String fname) throws IOException{ String path=session.getServletContext().getRealPath("/"); File f=new File(path+"prop/"+fname+".properties"); if(!f.exists()){ f.getParentFile().mkdirs(); } if(!f.exists()){ try { f.createNewFile(); ...
很多时候用 exists 代替 in 是一个好的选择:select num from a where num in(select num from b) 用下面的语句替换:select num from a where exists(select 1 from b where num=a.num)并不是所有索引对查询都有效,SQL 是根据表中数据来进行查询优化的,当索引 列有大量数据重复时,SQL 查询可能不会去利用...
This approach has the advantage that the party who unseals the object does not need to keep track of the parameters (e.g., the IV) that were used to seal the object.The Mac ClassSimilar to a MessageDigest, a Message Authentication Code (MAC) provides a way to check the integrity of ...
异常处理、多线程、集合框架、File类与IO流、网络编程、日期相关的API与比较器、反射、Java8-17新特征 语言= 语法 + 逻辑 2. 计算机的构成# 硬件:CPU、内存、硬盘、输入设备、输出设备、调制解调器 软件 3. 软件# 软件:即一系列按照特定顺序组织的计算机数据和指令的集合。
import java.nio.file.Paths; import java.nio.file.StandardOpenOption; import java.util.EnumSet; import static java.nio.file.LinkOption.NOFOLLOW_LINKS; public class Main { public static void deleteCopied(Path path){ try { Files.deleteIfExists(path); ...
8037044 install install unpack200.exe calls are broken on windows 8037267 install install zh-SG (Chinese Singapore) locale should be handled as Chinese Simplified 8038395 install install enterprise MSI PIT has 2 major issues 8039085 install install Unittests for new functionality in FileUtils is requ...
security.checkLink(filename); } if(!(newFile(filename).isAbsolute())) { thrownewUnsatisfiedLinkError( "Expecting an absolute path of the library: "+ filename); } ClassLoader.loadLibrary(fromClass, filename,true); } loadLibrary() System 类提供...
When creating a connection, client TLS behavior is set while creating options. The client assumes TLS is requested if there is an SSLContext instance in the options. There are two ways one exists: The user directly supplied one A default one was created since one was not supplied, but a ...