问DataInputStream编码
EN

Stack Overflow用户

提问于 2018-09-16 07:02:23

回答 3查看 1K关注 0票数 2

我需要在"ISO-8859-1“中编码我的文件。我知道怎么用这样的阅读器做这件事：

BufferedReader br = new BufferedReader(new InputStreamReader(
            new FileInputStream(src), "ISO-8859-1"))

但我想问的是如何像这样编码DataInputStream。

我现在的解密：

DataInputStream dit = new DataInputStream(new BufferedInputStream(
            new FileInputStream(src)))

我更喜欢一种解决方案，其中编码参数在解密。我想要读的数据是用DataOutputStream编写的。

DataStreams的导入方法和导出方法：

public void importDST(String src) throws FileNotFoundException, IOException{
    try (DataInputStream dit = new DataInputStream(new BufferedInputStream(new FileInputStream(src)))) {
        while(dit.available() > 0) {
            pupils.add(new Pupil(dit.readInt(), dit.readInt(), dit.readUTF(), dit.readUTF(), dit.readChar(),
                    dit.readUTF(), dit.readInt(), dit.readInt(), dit.readInt(), dit.readUTF(), dit.readUTF(), dit.readUTF(), dit.readUTF(),
                    dit.readUTF(), dit.readUTF()));
        }
    } catch (FileNotFoundException e) {
        throw e;
    } catch (IOException e) {
        throw e;
    }
}

public void exportDST(String dest, ArrayList<Pupil> pupils) throws FileNotFoundException, IOException{
    this.pupils = pupils;
    try (DataOutputStream dot = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(dest)))) {
        for (Pupil p : this.pupils) {
            dot.writeInt(p.getId());
            dot.writeInt(p.getNumber());
            dot.writeUTF(p.getFirstname());
            dot.writeUTF(p.getLastname());
            dot.writeChar(p.getGender());
            dot.writeUTF(p.getReligion());
            dot.writeInt(p.getDay());
            dot.writeInt(p.getMonth());
            dot.writeInt(p.getYear());
            dot.writeUTF(p.getStreet());
            dot.writeUTF(p.getPlz());
            dot.writeUTF(p.getLocation());
            dot.writeUTF(p.getShortName());
            dot.writeUTF(p.getClassName());
            dot.writeUTF(p.getKvLastname());
        }
    } catch (FileNotFoundException e) {
        throw e;
    } catch (IOException e) {
        throw e;
    }
}

班级学生：

public class Pupil implements Serializable{
private int id;
private int number;
private String firstname;
private String lastname;
private char gender;
private String religion;
private int day;
private int month;
private int year;
private String street;
private String plz;
private String location;
private String shortName;
private String className;
private String kvLastname;

public Pupil() {}

public Pupil(int id, int number, String firstname, String lastname, char gender,
             String religion, int day, int month, int year, String street, String plz, String location,
             String shortName, String className, String kvLastname) {
    this.id = id;
    this.number = number;
    this.firstname = firstname;
    this.lastname = lastname;
    this.gender = gender;
    this.religion = religion;
    this.day = day;
    this.month = month;
    this.year = year;
    this.street = street;
    this.plz = plz;
    this.location = location;
    this.shortName = shortName;
    this.className = className;
    this.kvLastname = kvLastname;
}
}

java

character-encoding

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回答 3

Stack Overflow用户

回答已采纳

发布于 2018-09-17 11:33:38

我绕过这个问题，只写和读Ints和Bytes，而不是String。我读取字节数组，并使用它的编码创建了一个新字符串。以下是修改后的代码：

阅读：

public void importDST(String src) throws IOException{
    try (DataInputStream dit = new DataInputStream(new BufferedInputStream(new FileInputStream(src)))) {
        while (dit.available() > 0) {
            Pupil p = new Pupil();
            byte[] arr;
            int len;

            p.setId(dit.readInt());
            p.setNumber(dit.readInt());
            len = dit.readInt();
            arr = new byte[len];
            dit.readFully(arr);
            p.setFirstname(new String(arr, "ISO-8859-1"));
            len = dit.readInt();
            arr = new byte[len];
            dit.readFully(arr);
            p.setLastname(new String(arr, "ISO-8859-1"));
            p.setGender(dit.readChar());
            len = dit.readInt();
            arr = new byte[len];
            dit.readFully(arr);
            p.setReligion(new String(arr, "ISO-8859-1"));
            p.setDay(dit.readInt());
            p.setMonth(dit.readInt());
            p.setYear(dit.readInt());
            len = dit.readInt();
            arr = new byte[len];
            dit.readFully(arr);
            p.setStreet(new String(arr, "ISO-8859-1"));
            p.setPlz(dit.readInt());
            len = dit.readInt();
            arr = new byte[len];
            dit.readFully(arr);
            p.setLocation(new String(arr, "ISO-8859-1"));
            len = dit.readInt();
            arr = new byte[len];
            dit.readFully(arr);
            p.setShortName(new String(arr, "ISO-8859-1"));
            len = dit.readInt();
            arr = new byte[len];
            dit.readFully(arr);
            p.setClassName(new String(arr, "ISO-8859-1"));
            len = dit.readInt();
            arr = new byte[len];
            dit.readFully(arr);
            p.setKvLastname(new String(arr, "ISO-8859-1"));

            pupils.add(p);
        }
    }
}

写作：

public void exportDST(String dest, ArrayList<Pupil> pupils) throws IOException{
    this.pupils = pupils;
    try (DataOutputStream dot = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(dest)))) {
        for (Pupil p : pupils) {
            dot.writeInt(p.getId());
            dot.writeInt(p.getNumber());
            dot.writeInt(p.getFirstname().length());
            dot.writeBytes(p.getFirstname());
            dot.writeInt(p.getLastname().length());
            dot.writeBytes(p.getLastname());
            dot.writeChar(p.getGender());
            dot.writeInt(p.getReligion().length());
            dot.writeBytes(p.getReligion());
            dot.writeInt(p.getDay());
            dot.writeInt(p.getMonth());
            dot.writeInt(p.getYear());
            dot.writeInt(p.getStreet().length());
            dot.writeBytes(p.getStreet());
            dot.writeInt(p.getPlz());
            dot.writeInt(p.getLocation().length());
            dot.writeBytes(p.getLocation());
            dot.writeInt(p.getShortName().length());
            dot.writeBytes(p.getShortName());
            dot.writeInt(p.getClassName().length());
            dot.writeBytes(p.getClassName());
            dot.writeInt(p.getKvLastname().length());
            dot.writeBytes(p.getKvLastname());
        }
    }
}