控制台程序，本例读取Java基础之写文件部分（PrimesToFile2）写入的Primes.txt。
方法一：可以在第一个读操作中读取字符串的长度，然后再将字符串和二进制素数值读入到文本中。这种方式的唯一不足是：这不是一种有效读取文件的方式，因为有很多的读操作，其中的每个都读取非常少量的数据。
import java.nio.file.*;
import java.nio.channels.FileChannel;
import java.io.IOException;
import java.nio.ByteBuffer; public class ReadPrimesMixedData {
public static void main(String[] args) {
Path file = Paths.get(System.getProperty("user.home")).resolve("Beginning Java Struff").resolve("primes.txt");
if(!Files.exists(file)) {
System.out.println(file + " does not exist. Terminating program.");
System.exit(1);;
} try (FileChannel inCh = (FileChannel)Files.newByteChannel(file)){
ByteBuffer lengthBuf = ByteBuffer.allocate(8);
int strLength = 0; // Stores the string length ByteBuffer[] buffers = {
null, // Byte buffer to hold string
ByteBuffer.allocate(8) // Byte buffer to hold prime
}; while(true) {
if(inCh.read(lengthBuf) == -1) // Read the string length,
break; // if its EOF exit the loop lengthBuf.flip(); // Extract the length and convert to int
strLength = (int)lengthBuf.getDouble(); // Now create the buffer for the string
buffers[0] = ByteBuffer.allocate(2*strLength); if(inCh.read(buffers) == -1) { // Read the string & binary prime value
// Should not get here!
System.err.println("EOF found reading the prime string.");
break; // Exit loop on EOF
} System.out.printf(
"String length: %3s String: %-12s Binary Value: %3d%n",
strLength,
((ByteBuffer)(buffers[0].flip())).asCharBuffer().toString(),
((ByteBuffer)buffers[1].flip()).getLong()); // Clear the buffers for the next read
lengthBuf.clear();
buffers[1].clear();
}
System.out.println("\nEOF reached.");
} catch(IOException e) {
e.printStackTrace();
}
}
}