jsp文件操作之讀取篇
2024-09-05 00:20:45
供稿：網友
文件操作是網站編程的重要內容之一，asp關于文件操作討論的已經很多了，讓我們來看看jsp中是如何實現的。
這里用到了兩個文件，一個jsp文件一個javabean文件，通過jsp中調用javabean可以輕松讀取文本文件，注意請放置一個文本文件afile.txt到web根目錄的test目錄下，javabean文件編譯后將class文件放到對應的class目錄下(tomcat環境)。
Read.jsp
<html>
<head>
<title>讀取一個文件</title>
</head>
<body bgcolor="#000000">
<%--調用javabean --%>
<jsp:useBean id="reader" class="DelimitedDataFile" scope="request">
<jsp:setProperty name="reader" property="path" value="/test/afile.txt" />
</jsp:useBean>
<h3>文件內容:</h3>
<p>
<% int count = 0; %>
<% while (reader.nextRecord() != -1) { %>
<% count++; %>
<b>第<% out.print(count); %>行:</b>
<% out.print(reader.returnRecord()); %><br>
<% } %>
</p>
</body>
</html>
//DelimitedDataFile.java bean文件源代碼
//導入java包
import java.io.*;
import java.util.StringTokenizer;
public class DelimitedDataFile
{
private String currentRecord = null;
private BufferedReader file;
private String path;
private StringTokenizer token;
//創建文件對象
public DelimitedDataFile()
{
file = new BufferedReader(new InputStreamReader(System.in),1);
}
public DelimitedDataFile(String filePath) throws FileNotFoundException
{
path = filePath;
file = new BufferedReader(new FileReader(path));
}
//設置文件路徑
public void setPath(String filePath)
{
path = filePath;
try {
file = new BufferedReader(new
FileReader(path));
} catch (FileNotFoundException e) {
System.out.println("file not found");
}
}
//得到文件路徑
public String getPath() {
return path;
}
//關閉文件
public void fileClose() throws IOException
{
file.close();
}
//讀取下一行記錄，若沒有則返回-1
public int nextRecord()
{
int returnInt = -1;
try
{
currentRecord = file.readLine();
}
catch (IOException e)
{
System.out.println("readLine problem, terminating.");
}
if (currentRecord == null)
returnInt = -1;
else
{
token = new StringTokenizer(currentRecord);
returnInt = token.countTokens();
}
return returnInt;
}
//以字符串的形式返回整個記錄
public String returnRecord()
{
return currentRecord;
}
}
