Java 输出文件新行未从下一行开始
我的空间有问题。 如何正确打印输出文件? 当我运行我的代码时,就像 这就是我的主方法的外观,并生成输出文件Java 输出文件新行未从下一行开始,java,junit,output,filewriter,bufferedwriter,Java,Junit,Output,Filewriter,Bufferedwriter,我的空间有问题。 如何正确打印输出文件? 当我运行我的代码时,就像 这就是我的主方法的外观,并生成输出文件 main()....{ File stats = new File(statFile); stats.createNewFile(); // my code here.... the stat values change here. FileWriter statFileWriter = new FileWriter(stats, true); Buffer
main()....{
File stats = new File(statFile);
stats.createNewFile();
// my code here.... the stat values change here.
FileWriter statFileWriter = new FileWriter(stats, true);
BufferedWriter statsOutput = new BufferedWriter(statFileWriter);
statsOutput.write(Stats.printStat());
statsOutput.flush();
}
这是一个Stat类,我可以更改程序中的值,并打印带有这些值的字符串
public class Stats {
public static String dataFile = "";
public static int cacheHits = 0;
public static int diskReads = 0;
public static int diskWrites = 0;
public static long executionTime = 0;
public static String printStat() {
String print = "";
print += "Sort on " + dataFile;
print += "\nCache Hits: " + cacheHits;
print += "\nDisk Reads: " + diskReads;
print += "\nDisk Writes: " + diskWrites;
print += "\nTime is " + executionTime;
return print;
}
}
这将使输出类似于:
Sort on sorted_b.dat
Cache Hits: 30922
Disk Reads: 1
Disk Writes: 1
Time is 16
Sort on sorted_a.dat
Cache Hits: 62899
Disk Reads: 2
Disk Writes: 2
Time is 0
但当我在testcase中两次运行main时,实际输出是:
Sort on sorted_b.dat
Cache Hits: 30922
Disk Reads: 1
Disk Writes: 1
Time is 16Sort on sorted_a.dat ------> the new stat is not start from the nextline.
Cache Hits: 62899
Disk Reads: 2
Disk Writes: 2
Time is 0
如果我在末尾添加额外的“/n”
打印+=“\n时间为”+执行时间;这条线,像
打印+=“\n时间为”+执行时间+\n
它将在末尾多出一行,如
Sort on sorted_b.dat
Cache Hits: 30922
Disk Reads: 1
Disk Writes: 1
Time is 16
Sort on sorted_a.dat
Cache Hits: 62899
Disk Reads: 2
Disk Writes: 2
Time is 0
------------blank, but extra line.
如何在没有额外行的情况下打印输出并正确打印?您需要在末尾附加额外的“\n”
在main方法中,只需使用
BufferedWriter
的方法,如下所示:
FileWriter statFileWriter = new FileWriter(stats, true);
BufferedWriter statsOutput = new BufferedWriter(statFileWriter);
statsOutput.write(Stats.printStat());
statsOutput.newLine();
如果愿意,您还可以在写入统计数据之前添加新行。将主方法更改为:
File stats = new File(statFile);
Boolean fromStart = stats.createNewFile();
// my code here.... the stat values change here.
FileWriter statFileWriter = new FileWriter(stats, true);
BufferedWriter statsOutput = new BufferedWriter(statFileWriter);
if(fromStart == false) statsOutput.write("\n");
statsOutput.write(Stats.printStat());
statsOutput.flush();
从stats.createNewFile()返回的Boolean fromStart
将是:
如果文件是第一次创建-->无需添加额外的换行符true
如果文件已存在-->需要在写入新内容之前添加换行符false
printStat()
输出到同一个文件中。在连续调用printStat()
之间输出换行符。编辑以更正换行符打印(doh)的位置
File stats = new File(statFile);
Boolean fromStart = stats.createNewFile();
// my code here.... the stat values change here.
FileWriter statFileWriter = new FileWriter(stats, true);
BufferedWriter statsOutput = new BufferedWriter(statFileWriter);
if(fromStart == false) statsOutput.write("\n");
statsOutput.write(Stats.printStat());
statsOutput.flush();