Question

我正在尝试通过替换文件中的3行来编辑build.prop文件。以下方法保留原始行并将新行复制到新文件。我需要更换行而不是添加新行。

我已更新我的代码以使用下面显示的“else if”

/**Changing build.prop values here
* @throws IOException */

public void PropEdit() throws InterruptedException, IOException
{
String origFile = "data/data/vzw.versatile1.props/build.orig.prop";
String propFile = "data/data/vzw.versatile1.props/build.new.prop";
try {
suProcess = Runtime.getRuntime().exec("su");
DataOutputStream os = new DataOutputStream(suProcess.getOutputStream());
os.writeBytes("chmod 777 /data/data/vzw.versatile1.props/build.new.prop\n");

BufferedReader in = new BufferedReader(new FileReader(origFile));
PrintWriter out = new PrintWriter(new File(propFile));

String line; 
String params [];

while ((line = in.readLine()) != null) {
params = line.split("=");  
if 
(params[0].equalsIgnoreCase("ro.product.device")) {
out.println(params[0] + "=" + "Maguro");
/**out.println(line); **/
out.flush();
} else
if 
(params[0].equalsIgnoreCase("ro.product.name")) 
{ 
out.println(params[0] + "=" + "yakju");
/**out.println(line); **/
out.flush();
} else if (params[0].equalsIgnoreCase("ro.product.model")) 
{
out.println(params[0] + "=" + "Galaxy Nexus");
/**out.println(line); **/
out.flush();
}
out.println(line);
}
boolean successful;
{
out.close();
in.close();
os.flush();
os.close();
suProcess.waitFor();

}   
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "ERROR: " + e.getMessage(), Toast.LENGTH_SHORT).show();
        e.printStackTrace();
}
}

Answer 1

更改此代码：

if ("ro.device.name".equals(params[0]))
    out.println(params[0] + "=" + Galaxy Nexus); 
} else {
    out.println(line);
}

收件人（请注意{行末尾的if：

if ("ro.device.name".equals(params[0])) {
    out.println(params[0] + "=" + Galaxy Nexus); 
} else {
    out.println(line);
}

Answer 2

编辑：如果我理解正确，应该这样做：

//your while loop
// if you have exact 3 cases, you can do this.
while ((line = in.readLine()) != null) {
    params = line.split("="); 
    if ("ro.device.name".equalsIgnoreCase(params[0])) {
        out.println(params[0] + "=" + "Galaxy Nexus"); 
    } else if ("ro.device.product".equalsIgnoreCase(params[0])) {
        out.println(params[0] + "=" + "some String"); 
    } else if ("ro.device.whatever".equalsIgnoreCase(params[0])) {
        out.println(params[0] + "=" + "another String"); 
    } else {
        out.println(line);
    }
}

也许您遇到区分大小写的问题。你可以尝试

"ro.device.name".equalsIgnoreCase(params[0])

或者，我认为replaceAll也适合这种任务。

line = line.replaceAll("(?i)" + "ro.device.name=Galaxy Nexus",);

或者

public static void replace(String oldstring, String newstring, File in, File out)
throws IOException {
    BufferedReader reader = new BufferedReader(new FileReader(in));
    PrintWriter writer = new PrintWriter(new FileWriter(out));
    String line = null;
    while ((line = reader.readLine()) != null)
        writer.println(line.replaceAll("(?i)" + oldstring,newstring));
    reader.close();
    writer.close();
}

注意“（？i）”用于忽略大小写。

替换文件中的多行不起作用

2 个答案: