How to convert Strings to and from UTF8 byte arrays in Java

Question

In Java, I have a String and I want to encode it as a byte array (in UTF8, or some other encoding). Alternately, I have a byte array (in some known encoding) and I want to c

Answer 1

For decoding a series of bytes to a normal string message I finally got it working with UTF-8 encoding with this code:

/* Convert a list of UTF-8 numbers to a normal String
 * Usefull for decoding a jms message that is delivered as a sequence of bytes instead of plain text
 */
public String convertUtf8NumbersToString(String[] numbers){
    int length = numbers.length;
    byte[] data = new byte[length];

    for(int i = 0; i< length; i++){
        data[i] = Byte.parseByte(numbers[i]);
    }
    return new String(data, Charset.forName("UTF-8"));
}

Answer 2

terribly late but i just encountered this issue and this is my fix:

private static String removeNonUtf8CompliantCharacters( final String inString ) {
    if (null == inString ) return null;
    byte[] byteArr = inString.getBytes();
    for ( int i=0; i < byteArr.length; i++ ) {
        byte ch= byteArr[i]; 
        // remove any characters outside the valid UTF-8 range as well as all control characters
        // except tabs and new lines
        if ( !( (ch > 31 && ch < 253 ) || ch == '\t' || ch == '\n' || ch == '\r') ) {
            byteArr[i]=' ';
        }
    }
    return new String( byteArr );
}

Answer 3

//query is your json   

 DefaultHttpClient httpClient = new DefaultHttpClient();
 HttpPost postRequest = new HttpPost("http://my.site/test/v1/product/search?qy=");

 StringEntity input = new StringEntity(query, "UTF-8");
 input.setContentType("application/json");
 postRequest.setEntity(input);   
 HttpResponse response=response = httpClient.execute(postRequest);

Answer 4

Charset UTF8_CHARSET = Charset.forName("UTF-8");
String strISO = "{\"name\":\"א\"}";
System.out.println(strISO);
byte[] b = strISO.getBytes();
for (byte c: b) {
    System.out.print("[" + c + "]");
}
String str = new String(b, UTF8_CHARSET);
System.out.println(str);

Answer 5

String original = "hello world";
byte[] utf8Bytes = original.getBytes("UTF-8");

Answer 6

As an alternative, StringUtils from Apache Commons can be used.

 byte[] bytes = {(byte) 1};
 String convertedString = StringUtils.newStringUtf8(bytes);

or

 String myString = "example";
 byte[] convertedBytes = StringUtils.getBytesUtf8(myString);

If you have non-standard charset, you can use getBytesUnchecked() or newString() accordingly.