如何在Java中从字节数组中获取数据?
我使用如何在Java中从字节数组中获取数据?,java,c,struct,bytearray,bytebuffer,Java,C,Struct,Bytearray,Bytebuffer,我使用字节[512]从Java中的套接字接收数据 我使用函数bytesToHexString使其可见 public static String bytesToHexString(byte[] src) { StringBuilder stringBuilder = new StringBuilder(""); if (src == null || src.length <= 0) { return null; } for (int i = 0
字节[512]
从Java中的套接字接收数据
我使用函数bytesToHexString
使其可见
public static String bytesToHexString(byte[] src) {
StringBuilder stringBuilder = new StringBuilder("");
if (src == null || src.length <= 0) {
return null;
}
for (int i = 0; i < src.length; i++) {
int v = src[i] & 0xFF;
String hv = Integer.toHexString(v);
if (hv.length() < 2) {
stringBuilder.append(0);
}
stringBuilder.append(hv + " ");
}
return stringBuilder.toString();
}
我知道的是C中的这个结构:
typedef struct _xchip_cmd_head {
u16 flag; //always 50 1c
u16 cmd; // commands, return cmd=cmd|0x8000
u16 cmd_status; //return result
u16 datalen;
u8 data[1];
}xchip_cmd_head_t;
50 1c
是启动标志
0480
是命令
00
是一种状态
ce 01
是数据的长度
在ce 01之后
是ssid的列表:
typedef struct _ApList_str
{
char ssid[32];
char ApPower; // min:0, max:100
}ApList_str;
那么,如何在Java中获取ssid列表呢
我做了一些搜索,有没有办法使用ByteBuffer
?50 1c是开始标志
0480是命令
00是一种状态
ce 01是ssid列表长度
如果上面的列表是常量,就像应用程序协议缓冲区一样,那么您可以解析bytearray并打印值。
检查radius数据包的解析。您不能说
ApPower
编码在哪里,否则这个类将执行您想要的操作
public class ApList_str {
private final String ssid;
private int ApPower = -1; /* Unknown */
public ApList_str(String ssid) {
this.ssid = ssid;
}
public String getSsid() {
return ssid;
}
public int getApPower() {
return ApPower;
}
public void setApPower(int apPower) {
ApPower = apPower;
}
public static ApList_str fromBytes(ByteBuffer b) throws UnsupportedEncodingException {
byte[] ssid_bytes = new byte[32];
b.get(ssid_bytes);
/* You should change the encoding depending on your situation */
return new ApList_str(new String(ssid_bytes, "UTF-8"));
}
}
最后,我通过这个函数获取了
ssid
列表。这看起来很愚蠢,但很管用
我想找到更好的方法:
public static List<String> getSsidList(byte[] byteRecv) {
System.out.println("get from device");
List<String> ssidListOpt = new ArrayList<String>();
try {
if (byteRecv[0] != 0) {
// make it visabled
String test = BytesUtil.bytesToHexString(byteRecv);
// replace the space
test = test.replace(" ", "");
// get rid of the head data
test = test.substring(16);
String temp = "";
// split the ssid,add "," between every ssid item
for (int i = 0; i < test.length(); i++) {
if (i % 66 == 0 && i != 0) {
temp += ",";
}
temp += test.substring(i, i + 1);
}
// put it into the string array
String temps[] = temp.split(",");
for (int i = 0; i < temps.length; i++) {
if (temps[i].endsWith("00")) {
continue;
}
int l = temps[i].length();
// get the hex ssid name
String ssidName = temps[i].substring(0, l - 2);
// delete all of 0x00 at the end
ssidName = BytesUtil.deleteLastZero(ssidName);
// hex ssid name to string
ssidName = BytesUtil.toStringHex(ssidName);
if ("".equals(ssidName)) {
continue;
}
// get the hex ApPower
String signal = temps[i].substring(l - 2, l);
// hex to int
signal = Integer.parseInt(signal, 16) + "";
String t[] = {ssidName, signal};
System.out.println("" + t[0] + "------" + t[1]);
ssidListOpt.add(ssidName);
}
}
} catch (Exception e) {
e.printStackTrace();
}
return ssidListOpt;
}
那么如何解析它呢?如何将此十六进制值转换为字符串?可能是通过此链接将十六进制值转换为字符串,反之则有点不清楚您想要什么:您已经成功解析了Java端的字节数组,甚至将内容打印为十六进制字符串,您没有做什么?@gio我想做的是拆分ssid的字符串,然后把它放到
列表中
嗨,但是我还不知道如何使用这个类。我得到的是一个字节[512]
以及如何拆分这个字节数组???您可以使用ByteBuffer.wrap()?
public static List<String> getSsidList(byte[] byteRecv) {
System.out.println("get from device");
List<String> ssidListOpt = new ArrayList<String>();
try {
if (byteRecv[0] != 0) {
// make it visabled
String test = BytesUtil.bytesToHexString(byteRecv);
// replace the space
test = test.replace(" ", "");
// get rid of the head data
test = test.substring(16);
String temp = "";
// split the ssid,add "," between every ssid item
for (int i = 0; i < test.length(); i++) {
if (i % 66 == 0 && i != 0) {
temp += ",";
}
temp += test.substring(i, i + 1);
}
// put it into the string array
String temps[] = temp.split(",");
for (int i = 0; i < temps.length; i++) {
if (temps[i].endsWith("00")) {
continue;
}
int l = temps[i].length();
// get the hex ssid name
String ssidName = temps[i].substring(0, l - 2);
// delete all of 0x00 at the end
ssidName = BytesUtil.deleteLastZero(ssidName);
// hex ssid name to string
ssidName = BytesUtil.toStringHex(ssidName);
if ("".equals(ssidName)) {
continue;
}
// get the hex ApPower
String signal = temps[i].substring(l - 2, l);
// hex to int
signal = Integer.parseInt(signal, 16) + "";
String t[] = {ssidName, signal};
System.out.println("" + t[0] + "------" + t[1]);
ssidListOpt.add(ssidName);
}
}
} catch (Exception e) {
e.printStackTrace();
}
return ssidListOpt;
}
02-06 15:06:40.398: I/System.out(20947): Modim fashion------100
02-06 15:06:40.398: I/System.out(20947): tessgz2------80
02-06 15:06:40.398: I/System.out(20947): sweet baby------67
02-06 15:06:40.398: I/System.out(20947): wz------62
02-06 15:06:40.408: I/System.out(20947): Bert-Co------45
02-06 15:06:40.408: I/System.out(20947): ChinaNet-GPi6------40
02-06 15:06:40.408: I/System.out(20947): ringierguest------40
02-06 15:06:40.408: I/System.out(20947): tlessgz1------32
02-06 15:06:40.408: I/System.out(20947): JIMMY 3G------32
02-06 15:06:40.408: I/System.out(20947): blue1------30
02-06 15:06:40.408: I/System.out(20947): ChinaNet-Ul6------25
02-06 15:06:40.408: I/System.out(20947): wudiuandiuan------15