將數據寫入字符串

Question

這可能非常容易解決，但我暫時停留了一段時間。我用了一個while循環來寫數據。我想將while循環中的數據寫入String。

public void dumpPart(Part p) throws Exception { 
    InputStream is = p.getInputStream(); 
    if (!(is instanceof BufferedInputStream)) { 
     is = new BufferedInputStream(is); 
    } 
    int c; 
    System.out.println("Message: "); 
    while ((c = is.read()) != -1) { 
     System.out.write(c); //I want to write this data to a String. 

    } 
    sendmail.VerstuurEmail(mpMessage, kenmerk); 
} 

解決：

public void dumpPart(Part p) throws Exception { 
    InputStream is = p.getInputStream(); 
    if (!(is instanceof BufferedInputStream)) { 
     is = new BufferedInputStream(is); 
    } 
    int c; 
    final StringWriter sw = new StringWriter(); 
    System.out.println("Message: "); 
    while ((c = is.read()) != -1) { 
     sw.write(c); 
    } 
    mpMessage = sw.toString();; 
    sendmail.VerstuurEmail(mpMessage, kenmerk); 
} 

感謝您的幫助。

Answer 1

，可以考慮一個java.io.StringWriter（如JDK的1.4+）：

System.out.println("Message: "); 

final StringWriter sw = new StringWriter(); 

int c; 
while ((c = is.read()) != -1) { 
    sw.write(c); 
} 

String data = sw.toString(); 

Answer 2

取而代之的是System.out的呼叫循環之前只是初始化一個StringBuffer和追加到它：

StringBuffer s = new StringBuffer(); 
while ((c = is.read()) != -1) { 
    s.append((char) c); 
} 

Answer 3

我會用IOUtils.toString(inputStream)或類似的東西。

Answer 4

它最好使用StringBuilder對象，而不是StringBuffer的（Difference between StringBuilder and StringBuffer）

public void dumpPart(Part p) throws Exception { 
    InputStream is = p.getInputStream(); 
    if (!(is instanceof BufferedInputStream)) { 
     is = new BufferedInputStream(is); 
    } 
    int c; 
    StringBuilder sb = new StringBuilder(); 
    System.out.println("Message: "); 
    while ((c = is.read()) != -1) { 
     sb.append(c); 

    } 
    String result= sb.toString(); 
    sendmail.VerstuurEmail(mpMessage, kenmerk); 
} 

Answer 5

一種可能性是，做到這一點：

 int c; 
    System.out.println("Message: "); 
    StringWriter sw = new StringWriter(); 
    while ((c = is.read()) != -1) { 
     sw.write(c); 
    } 
    System.out.println(sw.toString()); 

Answer 6

另一種方式：

StringBuffer buffer = new StringBuffer(); 
byte[] b = new byte[4096]; 
for (int n; (n = is.read(b)) != -1;) { 
    buffer.append(new String(b, 0, n)); 
} 
String str = buffer.toString();