将 EBCDIC 字符串转换为 ASCII 格式？

Question

我有一个从 Db2 表中提取的平面文件，该平面文件包含 char 格式和打包十进制格式的记录。如何将打包数据转换为 java 字符串。有什么办法可以将整个平面文件转换为 ASCII 格式。

Answer 1

EBCDIC 是一个编码系列。您需要详细了解您所使用的 EBCDIC 编码。

Java有多个supported encodings，包括：

• IBM500/Cp500 - EBCDIC 500V1
• x-IBM834/Cp834 - IBM EBCDIC DBCS-only 韩语（双字节）
• IBM1047/Cp1047 - EBCDIC 主机的 Latin-1 字符集

试试这些，看看你会得到什么。比如：

InputStreamReader rdr = new InputStreamReader(new FileInputStream(<your file>), java.nio.Charset.forName("ibm500"));
    while((String line = rdr.readLine()) != null) {
        System.out.println(line);
}

Answer 2

将文件读取为字符串，将其写入为 EBCDIC。使用 OutputStreamWriter 和 InputStreamWriter 并在构造函数中给出编码。

Answer 3

继PAP之后，CP037是美国EBCDIC编码。

还可以查看JRecord 项目。它允许您读取具有 Cobol 或 Xml 描述的文件，并将处理 EBCDIC 和 Comp-3。

最后这里是一个将压缩十进制字节转换为字符串的例程，请参阅Conversion中的方法 getMainframePackedDecimal

Answer 4

我分享一个示例代码供您参考：

    package mypackage;
    import java.io.UnsupportedEncodingException;
    import java.math.BigInteger;
    public class EtoA {

public static void main(String[] args) throws UnsupportedEncodingException {

    System.out.println("########");
    String edata = "/ÂÄÀ"; //Some EBCDIC string ==> here the OP can provide the content of flat file which the OP pulled from DB2 table 
    System.out.println("ebcdic source to ascii:");
    System.out.println("ebcdic: " + edata);
    String ebcdic_encoding = "IBM-1047"; //Setting the encoding in which the source was encoded
    byte[] result = edata.getBytes(ebcdic_encoding); //Getting the raw bytes of the EBCDIC string by mentioning its encoding
    String output = asHex(result); //Converting the raw bytes into hexadecimal format
    byte[] b = new BigInteger(output, 16).toByteArray(); //Now its easy to convert it into another byte array (mentioning that this is of base16 since it is hexadecimal)
    String ascii = new String(b, "ISO-8859-1"); //Now convert the modified byte array to normal ASCII string using its encoding "ISO-8859-1"
    System.out.println("ascii: " + ascii); //This is the ASCII string which we can use universally in JAVA or wherever 

    //Inter conversions of similar type (ASCII to EBCDIC) are given below:
    System.out.println("########");
    String adata = "abcd";
    System.out.println("ascii source to ebcdic:");
    System.out.println("ascii: " + adata);
    String ascii_encoding = "ISO-8859-1";
    byte[] res = adata.getBytes(ascii_encoding);
    String out = asHex(res);
    byte[] bytebuff = new BigInteger(out, 16).toByteArray();
    String ebcdic = new String(bytebuff, "IBM-1047");
    System.out.println("ebcdic: " + ebcdic);

    //Converting from hexadecimal string to EBCDIC if needed
    System.out.println("########");
    System.out.println("hexcode to ebcdic");
    String hexinput = "81828384"; //Hexadecimal which we are converting to EBCDIC
    System.out.println("hexinput: " + hexinput);
    byte[] buffer = new BigInteger(hexinput, 16).toByteArray();
    String eout = new String(buffer, "IBM-1047");
    System.out.println("ebcdic out:" + eout);

    //Converting from hexadecimal string to ASCII if needed
    System.out.println("########");
    System.out.println("hexcode to ascii");
    String hexin = "61626364";
    System.out.println("hexin: " + hexin);
    byte[] buff = new BigInteger(hexin, 16).toByteArray();
    String asciiout = new String(buff, "ISO-8859-1");
    System.out.println("ascii out:" + asciiout);
}

//This asHex method converts the given byte array to a String of Hexadecimal equivalent
public static String asHex(byte[] buf) {
    char[] HEX_CHARS = "0123456789abcdef".toCharArray();
    char[] chars = new char[2 * buf.length];
    for (int i = 0; i < buf.length; ++i) {
        chars[2 * i] = HEX_CHARS[(buf[i] & 0xF0) >>> 4];
        chars[2 * i + 1] = HEX_CHARS[buf[i] & 0x0F];
    }
    return new String(chars);
}
}