对于上传空文件
上传文件简单,但是如何创建一个空的输入流时突然难到了我。首先想到的是直接传null进入
得到的结果是
4: java.lang.NullPointerException
at com.jcraft.jsch.ChannelSftp._put(ChannelSftp.java:697)
at com.jcraft.jsch.ChannelSftp.put(ChannelSftp.java:540)
at com.jcraft.jsch.ChannelSftp.put(ChannelSftp.java:492)
at com.juneyaoair.com.SFTPTest.testAddEmptyFile2(SFTPTest.java:39)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)
Caused by: java.lang.NullPointerException
at com.jcraft.jsch.ChannelSftp._put(ChannelSftp.java:636)
... 25 more
第二次尝试
我想到了System.in 的源码 public final static InputStream in = null;
则出现的问题是程序hung住了。
第三次尝试
这次终于成功了,上面不停止的原因为没有收到-1
的结束标志
@Test
public void testAddEmptyFile2() {
Channel channel = null;
ChannelSftp sftp = null;
try {
JSch jSch = new JSch();
Session session = jSch.getSession("admin", "192.168.56.101", 2294);
session.setPassword("admin");
Properties config = new Properties();
config.put("StrictHostKeyChecking", "no");
session.setConfig(config);
session.connect();
channel = session.openChannel("sftp");
channel.connect();
sftp = (ChannelSftp) channel;
sftp.cd("/upload");
InputStream is = new InputStream() {
@Override
public int read() throws IOException {
return -1;//直接结束
}
};
sftp.put(is, "emptyFile.txt");
Vector<ChannelSftp.LsEntry> files = sftp.ls("/upload");
files.forEach(r -> System.out.println(r.getFilename()));
Assert.assertTrue(true);
} catch (Exception e) {
e.printStackTrace();
} finally {
assert sftp != null;
sftp.disconnect();
channel.disconnect();
}
}