这基本上是我想要做的。文件 - >字节[] - >字符串 - >字节[] - >文件转换
我想带一个文件
把它变成一个字节数组
把它变成一个字符串
储存于一个MySQL表
检索字符串
打开它回到一个字节阵列
T它回到一个文件
现在,我有一些代码给你,我试图评论尽我所能。我的问题是,我在这段代码的末尾得到的文件没有出来。它缺少信息。这是一个文本文件,所以我应该能够判断文件是否完整。
据我所见,它看起来像我只得到文件的最后部分,而不是整个文件。我很确定我在这个转换中的某个地方糟糕透顶。如果您对如何更有效地完成此转换和检索(仍然保留数据库及所有内容)有任何建议,请让我知道!
的代码下面列出
import java.io.*;
import java.util.StringTokenizer;
import java.util.logging.Level;
import java.util.logging.Logger;
public class main {
public static void main(String[] args) {
// The file we want to save.
File f = new File("build.xml");
try {
// Make it into a byte array first
FileInputStream fis = new FileInputStream(f);
ByteArrayOutputStream bos = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
try {
for(int readNum; (readNum = fis.read(buf)) != -1;) {
bos.write(buf, 0, readNum);
System.out.println("read " + readNum + " bytes,");
}
StringBuilder s = new StringBuilder();
// Now we simulate making it into a String, for easier storage
// in a database.
for(byte b : buf) {
// for debugging
s.append(b).append(",");
System.out.print(b +",");
}
// Now we want to retrieve the file from the database as a string
File someFile = new File("build2.xml");
FileOutputStream fos = new FileOutputStream(someFile);
// We count how many bytes there are in this string.
// One byte per Token.
StringTokenizer st = new StringTokenizer(s.toString(),",");
buf = new byte[st.countTokens()];
int i = 0;
StringBuilder t = new StringBuilder();
// Now we parse out all Bytes from the string, and put them into
// the prepared byte array.
while(st.hasMoreTokens()) {
byte b = Byte.parseByte(st.nextToken());
System.out.print(b + ",");
buf[i] = b;
i++;
// for debugging
t.append(b).append(",");
}
// Here I print true if both strings are exactly the same
// which they should be, which means that the bytes are intact
// before and after conversion.
System.out.println("\n" +(t.toString().equals(s.toString()) ? true : false));
// Here we would make the physical file on the machine.
fos.write(buf);
fos.flush();
fos.close();
} catch (IOException ex) {
Logger.getLogger(main.class.getName()).log(Level.SEVERE, null, ex);
}
} catch (FileNotFoundException ex) {
Logger.getLogger(main.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
将来,请将代码直接发布到您的问题中。 –
我总是弄错了,然后格式看起来很可怕。 – OmniOwl
使用代码示例将其与文本区分开来。 – Venki