Write data to a String

Question

This is probably very easy to solve, but I am stuck on this for a while now. I got a while loop which I use to write data. I want to write the data from the while loop to a 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);
}

Solved:

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);
}

Thanks for your help.

@PeterLawrey I want to store the data in just a String, sorry. — Jef, Sep 17 '12 at 11:19

score 6 · Accepted Answer · answered Sep 17 '12 at 11:20

6

You can consider a java.io.StringWriter (as of JDK 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();

answered Sep 17 '12 at 11:20

Alexandre Dupriez

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score 5 · Answer 2 · answered Sep 17 '12 at 11:19

5

I would use IOUtils.toString(inputStream) or something like it.

answered Sep 17 '12 at 11:19

Peter Lawrey

525,659
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1,130

this is what I'd prefer if you don't need the while-loop for other reasons. Just convert it with: `String sPart = IOUtils.toString(is);` – Herm Sep 17 '12 at 11:28

Dan D. · Answer 3 · 2012-09-17T11:25:32.033

2

Instead of the System.out call just initialize a StringBuffer before the loop and append to it:

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

edited Sep 17 '12 at 11:25

answered Sep 17 '12 at 11:18

Dan D.

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c is an `int` so it may not compile. – Peter Lawrey Sep 17 '12 at 11:20
2

I wouldn't use a StringBuffer if I can use a StringBuilder http://vanillajava.blogspot.co.uk/2012/08/java-memes-which-refuse-to-die.html – Peter Lawrey Sep 17 '12 at 11:23
Right. Just that the StringBuffer is compatible with the pre-1.5 era. – Dan D. Sep 17 '12 at 11:24

score 1 · Answer 4 · edited May 23 '17 at 11:55

Its best to do it using the StringBuilder Object rather than StringBuffer ( 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);
}

score 1 · Answer 5 · answered Sep 17 '12 at 11:24

1

One possibility is:

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

answered Sep 17 '12 at 11:24

Henrique

61
1
1

score 1 · Answer 6 · answered Sep 17 '12 at 11:28

1

One more way :

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();

answered Sep 17 '12 at 11:28

Santosh

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Write data to a String

6 Answers6