Android 读取文件中的前一行
我下面有一段代码,它可以读取一个未编号文件末尾的下一行(文件中的行没有编号),它工作得非常好。如果可能的话,洗牌(读随机线)。任何想法 以下是一个例子:Android 读取文件中的前一行,android,pointers,random,file-handling,Android,Pointers,Random,File Handling,我下面有一段代码,它可以读取一个未编号文件末尾的下一行(文件中的行没有编号),它工作得非常好。如果可能的话,洗牌(读随机线)。任何想法 以下是一个例子: InputStream in; BufferedReader reader; String qline; try { in = this.getAssets().open("quotations.txt"); reader = new BufferedReader(new InputStr
InputStream in;
BufferedReader reader;
String qline;
try {
in = this.getAssets().open("quotations.txt");
reader = new BufferedReader(new InputStreamReader(in));
qline = reader.readLine();
quote.setText(qline);
}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
在onClick方法中,我有一个用于下一步的按钮
//code
else if (v.getId() == R.id.next) {
try{
if (( qline = reader.readLine()) != null) {
// myData = myData + qline;
quote.setText(qline);
}
} catch (java.io.FileNotFoundException e) {
// do something if the myfilename.txt does not exits
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
else if (v.getId() == R.id.back) {
// code for the back option
}
您可以使用my library FileReader,也可以对其进行修改以适合您所寻求的功能:
// FileReader, Khaled A Khunaifer
public class FileReader
{
public static ArrayList<String> readAllLines (String path)
{
ArrayList<String> lines = new ArrayList<String>();
InputStream fis;
BufferedReader br;
String line;
try
{
fis = new FileInputStream(path);
br = new BufferedReader(new InputStreamReader(fis, Charset.forName("UTF-8")));
while ((line = br.readLine()) != null)
{
lines.add(line);
}
}
catch (Exception e)
{
e.printStackTrace()
}
return lines;
}
// NOTE: LINE NUMBERS START FROM 1
public static ArrayList<String> readLines (String path, long from, long to)
{
ArrayList<String> lines = new ArrayList<String>();
long k = 1;
InputStream fis;
BufferedReader br;
String line;
try
{
fis = new FileInputStream(path);
br = new BufferedReader(new InputStreamReader(fis, Charset.forName("UTF-8")));
do
{
line = br.readLine(); // read line k
if (k >= from)
{
if (k > to) break; // STOP
lines.add(line);
}
k++;
}
while (line != null);
}
catch (Exception e)
{
e.printStackTrace()
}
return line;
}
// NOTE: LINE NUMBERS START FROM 1
public static String readLine (String path, long i)
{
long k = 1;
InputStream fis;
BufferedReader br;
String line;
try
{
fis = new FileInputStream(path);
br = new BufferedReader(new InputStreamReader(fis, Charset.forName("UTF-8")));
do
{
line = br.readLine(); // read line k
if (k == i)
{
break;
}
k++;
}
while (line != null);
}
catch (Exception e)
{
e.printStackTrace()
}
return line;
}
}
//文件阅读器,Khaled A Khunaifer
公共类文件读取器
{
公共静态ArrayList readAllLines(字符串路径)
{
ArrayList行=新的ArrayList();
输入流fis;
缓冲剂;
弦线;
尝试
{
fis=新文件输入流(路径);
br=新的BufferedReader(新的InputStreamReader(fis,Charset.forName(“UTF-8”));
而((line=br.readLine())!=null)
{
行。添加(行);
}
}
捕获(例外e)
{
e、 printStackTrace()
}
回流线;
}
//注:行号从1开始
公共静态ArrayList读线(字符串路径、长从、长到)
{
ArrayList行=新的ArrayList();
长k=1;
输入流fis;
缓冲剂;
弦线;
尝试
{
fis=新文件输入流(路径);
br=新的BufferedReader(新的InputStreamReader(fis,Charset.forName(“UTF-8”));
做
{
line=br.readLine();//读取第k行
如果(k>=from)
{
如果(k>to)中断;//停止
行。添加(行);
}
k++;
}
while(line!=null);
}
捕获(例外e)
{
e、 printStackTrace()
}
回流线;
}
//注:行号从1开始
公共静态字符串读取线(字符串路径,长i)
{
长k=1;
输入流fis;
缓冲剂;
弦线;
尝试
{
fis=新文件输入流(路径);
br=新的BufferedReader(新的InputStreamReader(fis,Charset.forName(“UTF-8”));
做
{
line=br.readLine();//读取第k行
如果(k==i)
{
打破
}
k++;
}
while(line!=null);
}
捕获(例外e)
{
e、 printStackTrace()
}
回流线;
}
}
您可以使用my library FileReader,或对其进行修改以适应您所寻求的功能:
// FileReader, Khaled A Khunaifer
public class FileReader
{
public static ArrayList<String> readAllLines (String path)
{
ArrayList<String> lines = new ArrayList<String>();
InputStream fis;
BufferedReader br;
String line;
try
{
fis = new FileInputStream(path);
br = new BufferedReader(new InputStreamReader(fis, Charset.forName("UTF-8")));
while ((line = br.readLine()) != null)
{
lines.add(line);
}
}
catch (Exception e)
{
e.printStackTrace()
}
return lines;
}
// NOTE: LINE NUMBERS START FROM 1
public static ArrayList<String> readLines (String path, long from, long to)
{
ArrayList<String> lines = new ArrayList<String>();
long k = 1;
InputStream fis;
BufferedReader br;
String line;
try
{
fis = new FileInputStream(path);
br = new BufferedReader(new InputStreamReader(fis, Charset.forName("UTF-8")));
do
{
line = br.readLine(); // read line k
if (k >= from)
{
if (k > to) break; // STOP
lines.add(line);
}
k++;
}
while (line != null);
}
catch (Exception e)
{
e.printStackTrace()
}
return line;
}
// NOTE: LINE NUMBERS START FROM 1
public static String readLine (String path, long i)
{
long k = 1;
InputStream fis;
BufferedReader br;
String line;
try
{
fis = new FileInputStream(path);
br = new BufferedReader(new InputStreamReader(fis, Charset.forName("UTF-8")));
do
{
line = br.readLine(); // read line k
if (k == i)
{
break;
}
k++;
}
while (line != null);
}
catch (Exception e)
{
e.printStackTrace()
}
return line;
}
}
//文件阅读器,Khaled A Khunaifer
公共类文件读取器
{
公共静态ArrayList readAllLines(字符串路径)
{
ArrayList行=新的ArrayList();
输入流fis;
缓冲剂;
弦线;
尝试
{
fis=新文件输入流(路径);
br=新的BufferedReader(新的InputStreamReader(fis,Charset.forName(“UTF-8”));
而((line=br.readLine())!=null)
{
行。添加(行);
}
}
捕获(例外e)
{
e、 printStackTrace()
}
回流线;
}
//注:行号从1开始
公共静态ArrayList读线(字符串路径、长从、长到)
{
ArrayList行=新的ArrayList();
长k=1;
输入流fis;
缓冲剂;
弦线;
尝试
{
fis=新文件输入流(路径);
br=新的BufferedReader(新的InputStreamReader(fis,Charset.forName(“UTF-8”));
做
{
line=br.readLine();//读取第k行
如果(k>=from)
{
如果(k>to)中断;//停止
行。添加(行);
}
k++;
}
while(line!=null);
}
捕获(例外e)
{
e、 printStackTrace()
}
回流线;
}
//注:行号从1开始
公共静态字符串读取线(字符串路径,长i)
{
长k=1;
输入流fis;
缓冲剂;
弦线;
尝试
{
fis=新文件输入流(路径);
br=新的BufferedReader(新的InputStreamReader(fis,Charset.forName(“UTF-8”));
做
{
line=br.readLine();//读取第k行
如果(k==i)
{
打破
}
k++;
}
while(line!=null);
}
捕获(例外e)
{
e、 printStackTrace()
}
回流线;
}
}
好的,你可以使用Math.Random
输出所需范围的任意随机数。一旦你有了一个数字,就根据给定的随机数移动文件指针。这是你可以点击的链接。您可以使用Math.Random
输出所需范围内的任意随机数。一旦您有了一个数字,请根据给定的随机数移动文件指针。这是你可以点击的链接。