C结构写在文件上，Java开放 [英] C struct written in file, open with Java

问题描述

例如在C I具有结构：

For example in C I have structure:

typedef struct {
    int number;
    double x1;
    double y1;
    double x2;
    double y2;
    double x3;
    double y3;
} CTRstruct;`

然后我把它写到文件 FWRITE（安培; TR，1，sizeof的（TR），FP）; （TR - 其CTRstruct VAR，FP - 文件指针）

Then I write it to file fwrite(&tr, 1, sizeof(tr), fp); (tr - its CTRstruct var, fp - File pointer);

然后，我需要与Java读吧！我真的不知道如何从文件中读取结构......我试着用的ObjectInputStream（），最后的想法是用读来读它RandomAccessFile的（），但我也不知道如何...（ readLong（）的readDouble（）也不起作用，它工作ofcource但不读取正确的数据）。因此，任何想法如何使用Java读取二进制文件的C结构？

Then I need to read it with Java! I really don't know how to read struct from file... I tried to read it with ObjectInputStream(), last idea is to read with RandomAccessFile() but I also don't know how to... (readLong(), readDouble() also doesn't work, it works ofcource but doesn't read correct data). So, any idea how to read C struct from binary file with Java?

如果它很有趣，我的版本读取整（但它的丑陋，与放，我不知道该怎么办双击）

If it's interesting, my version to read integer (but it's ugly, & I don't know what to do with double):

公共类MyDataInputStream扩展DataInputStream以{

public class MyDataInputStream extends DataInputStream{

public MyDataInputStream(InputStream AIs) {
    super(AIs);
}

public int readInt1() throws IOException{
    int ch1 = in.read();
    int ch2 = in.read();
    int ch3 = in.read();
    int ch4 = in.read();
    if ((ch1 | ch2 | ch3 | ch4) < 0)
        throw new EOFException();
    return ((ch4 << 24) + (ch3 << 16) + (ch2 << 8) + (ch1 << 0));
}

---

双就可以处理相同的方式（如使用int或长（8个字节）及再转换与本机FUNC翻一番）。

---

with double we can deal the same way (like with int or with long (8bytes) & then convert to double with native func).

推荐答案

您必须找出你在执行的架构使用何种尺寸与C类型（int，double），因而该字节顺序（感谢安德鲁·库克）程序而在Java中使用同​​样大小的类型。

You have to find out what size those C types (int, double) and which endianness (thanks andrew cooke) are used in the architecture you executed the program in and use same sized types in Java.

这篇关于C结构写在文件上，Java开放的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！