最近開發了一個拍車牌識別車牌號的功能，主要調用了騰訊的ocr車牌識別接口，直接上代碼：
首先生成簽名以及讀取配置的工具類：
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package com.weaver.formmodel.integration.ocr; import java.util.random;import javax.crypto.mac;import javax.crypto.spec.secretkeyspec;import weaver.general.base64; public class signutil { /** * 生成 authorization 簽名字段 * * @param appid * @param secretid * @param secretkey * @param bucketname * @param expired * @return 簽名字符串 * @throws exception */ public static string appsign(long appid, string secretid, string secretkey, string bucketname, long expired) throws exception { long now = system.currenttimemillis() / 1000; int rdm = math.abs(new random().nextint()); string plaintext = string.format("a=%d&b=%s&k=%s&t=%d&e=%d&r=%d", appid, bucketname, secretid, now, now + expired, rdm); byte[] hmacdigest = hmacsha1(plaintext, secretkey); byte[] signcontent = new byte[hmacdigest.length + plaintext.getbytes().length]; system.arraycopy(hmacdigest, 0, signcontent, 0, hmacdigest.length); system.arraycopy(plaintext.getbytes(), 0, signcontent, hmacdigest.length, plaintext.getbytes().length); return base64encode(signcontent); } /** * 生成 base64 編碼 * * @param binarydata * @return */ public static string base64encode(byte[] binarydata) { string encodedstr = new string(base64.encode(binarydata)); return encodedstr; } /** * 生成 hmacsha1 簽名 * * @param binarydata * @param key * @return * @throws exception */ public static byte[] hmacsha1(byte[] binarydata, string key) throws exception { mac mac = mac.getinstance("hmacsha1"); secretkeyspec secretkey = new secretkeyspec(key.getbytes(), "hmacsha1"); mac.init(secretkey); byte[] hmacsha1digest = mac.dofinal(binarydata); return hmacsha1digest; } /** * 生成 hmacsha1 簽名 * * @param plaintext * @param key * @return * @throws exception */ public static byte[] hmacsha1(string plaintext, string key) throws exception { return hmacsha1(plaintext.getbytes(), key); }} |
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package weaver.general; import java.io.bufferedinputstream;import java.io.bufferedoutputstream;import java.io.bufferedreader;import java.io.bufferedwriter;import java.io.bytearrayoutputstream;import java.io.chararraywriter;import java.io.file;import java.io.fileinputstream;import java.io.fileoutputstream;import java.io.filereader;import java.io.filewriter;import java.io.inputstream;import java.io.outputstream;import java.io.reader;import java.io.writer; /** * provides encoding of raw bytes to base64-encoded characters, and decoding of * base64 characters to raw bytes. date: 06 august 1998 modified: 14 february * 2000 modified: 22 september 2000 * * @author kevin kelley ([email protected]) * @version 1.3 */public class base64 { /** * returns an array of base64-encoded characters to represent the passed * data array. * * @param data * the array of bytes to encode * @return base64-coded character array. */ public static char[] encode(byte[] data) { char[] out = new char[((data.length + 2) / 3) * 4]; // // 3 bytes encode to 4 chars. output is always an even // multiple of 4 characters. // for (int i = 0, index = 0; i < data.length; i += 3, index += 4) { boolean quad = false; boolean trip = false; int val = (0xff & data[i]); val <<= 8; if ((i + 1) < data.length) { val |= (0xff & data[i + 1]); trip = true; } val <<= 8; if ((i + 2) < data.length) { val |= (0xff & data[i + 2]); quad = true; } out[index + 3] = alphabet[(quad ? (val & 0x3f) : 64)]; val >>= 6; out[index + 2] = alphabet[(trip ? (val & 0x3f) : 64)]; val >>= 6; out[index + 1] = alphabet[val & 0x3f]; val >>= 6; out[index + 0] = alphabet[val & 0x3f]; } return out; } /** * decodes a base-64 encoded stream to recover the original data. white * space before and after will be trimmed away, but no other manipulation of * the input will be performed. * * as of version 1.2 this method will properly handle input containing junk * characters (newlines and the like) rather than throwing an error. it does * this by pre-parsing the input and generating from that a count of valid * input characters. **/ public static byte[] decode(char[] data) { // as our input could contain non-base64 data (newlines, // whitespace of any sort, whatever) we must first adjust // our count of usable data so that... // (a) we don't misallocate the output array, and // (b) think that we miscalculated our data length // just because of extraneous throw-away junk int templen = data.length; for (int ix = 0; ix < data.length; ix++) { if ((data[ix] > 255) || codes[data[ix]] < 0) --templen; // ignore non-valid chars and padding } // calculate required length: // -- 3 bytes for every 4 valid base64 chars // -- plus 2 bytes if there are 3 extra base64 chars, // or plus 1 byte if there are 2 extra. int len = (templen / 4) * 3; if ((templen % 4) == 3) len += 2; if ((templen % 4) == 2) len += 1; byte[] out = new byte[len]; int shift = 0; // # of excess bits stored in accum int accum = 0; // excess bits int index = 0; // we now go through the entire array (not using the 'templen' value) for (int ix = 0; ix < data.length; ix++) { int value = (data[ix] > 255) ? -1 : codes[data[ix]]; if (value >= 0)// skip over non-code { accum <<= 6; // bits shift up by 6 each time thru shift += 6; // loop, with new bits being put in accum |= value; // at the bottom. if (shift >= 8)// whenever there are 8 or more shifted in, { shift -= 8; // write them out (from the top, leaving any out[index++] = // excess at the bottom for next iteration. (byte) ((accum >> shift) & 0xff); } } // we will also have skipped processing a padding null byte ('=') // here; // these are used only for padding to an even length and do not // legally // occur as encoded data. for this reason we can ignore the fact // that // no index++ operation occurs in that special case: the out[] array // is // initialized to all-zero bytes to start with and that works to our // advantage in this combination. } // if there is still something wrong we just have to throw up now! if (index != out.length) { throw new error("miscalculated data length (wrote " + index + " instead of " + out.length + ")"); } return out; } // // code characters for values 0..63 // private static char[] alphabet = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789+/=" .tochararray(); // // lookup table for converting base64 characters to value in range 0..63 // private static byte[] codes = new byte[256]; static { for (int i = 0; i < 256; i++) codes[i] = -1; for (int i = 'a'; i <= 'z'; i++) codes[i] = (byte) (i - 'a'); for (int i = 'a'; i <= 'z'; i++) codes[i] = (byte) (26 + i - 'a'); for (int i = '0'; i <= '9'; i++) codes[i] = (byte) (52 + i - '0'); codes['+'] = 62; codes['/'] = 63; } // ///////////////////////////////////////////////// // remainder (main method and helper functions) is // for testing purposes only, feel free to clip it. // ///////////////////////////////////////////////// public static void main(string[] args) { boolean decode = false; if (args.length == 0) { system.out.println("usage: java base64 [-d[ecode]] filename"); system.exit(0); } for (int i = 0; i < args.length; i++) { if ("-decode".equalsignorecase(args[i])) decode = true; else if ("-d".equalsignorecase(args[i])) decode = true; } string filename = args[args.length - 1]; file file = new file(filename); if (!file.exists()) { system.out .println("error: file '" + filename + "' doesn't exist!"); system.exit(0); } if (decode) { char[] encoded = readchars(file); byte[] decoded = decode(encoded); writebytes(file, decoded); } else { byte[] decoded = readbytes(file); char[] encoded = encode(decoded); writechars(file, encoded); } } private static byte[] readbytes(file file) { bytearrayoutputstream baos = new bytearrayoutputstream(); try { inputstream fis = new fileinputstream(file); inputstream is = new bufferedinputstream(fis); int count = 0; byte[] buf = new byte[16384]; while ((count = is.read(buf)) != -1) { if (count > 0) baos.write(buf, 0, count); } is.close(); } catch (exception e) { e.printstacktrace(); } return baos.tobytearray(); } private static char[] readchars(file file) { chararraywriter caw = new chararraywriter(); try { reader fr = new filereader(file); reader in = new bufferedreader(fr); int count = 0; char[] buf = new char[16384]; while ((count = in.read(buf)) != -1) { if (count > 0) caw.write(buf, 0, count); } in.close(); } catch (exception e) { e.printstacktrace(); } return caw.tochararray(); } private static void writebytes(file file, byte[] data) { try { outputstream fos = new fileoutputstream(file); outputstream os = new bufferedoutputstream(fos); os.write(data); os.close(); } catch (exception e) { e.printstacktrace(); } } private static void writechars(file file, char[] data) { try { writer fos = new filewriter(file); writer os = new bufferedwriter(fos); os.write(data); os.close(); } catch (exception e) { e.printstacktrace(); } } // ///////////////////////////////////////////////// // end of test code. // ///////////////////////////////////////////////// } |
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package weaver.general; import java.io.file;import java.io.fileinputstream;import java.util.hashmap;import java.util.map;import java.util.properties; public class basebean { private static map<string, properties> propertymap = new hashmap<string, properties>(); public string getpropvalue(string config_file, string key) { if (propertymap.get(config_file) == null) { readpro(config_file); } properties pro = propertymap.get(config_file); return pro.getproperty(key); } private void readpro(string config_file) { properties pro = new properties(); fileinputstream in; try { string path = thread.currentthread().getcontextclassloader() .getresource("").tostring(); path = path.substring(6, path.indexof("classes/")); path = path + "prop/" + config_file + ".properties"; path = path.replace("%20", " "); system.out.println(path); file f = new file(path); if (!f.exists()) { throw new runtimeexception("要讀取的文件不存在"); } in = new fileinputstream(f); pro.load(in); in.close(); propertymap.put(config_file, pro); } catch (exception e) { e.printstacktrace(); } } } |
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package weaver.general; public class util { public static int getintvalue(string value) { try { return integer.parseint(value); } catch (numberformatexception e) { e.printstacktrace(); return 0; } } } |
然后是接口調配置文件：
正主來了，調用接口部分：
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package com.weaver.formmodel.integration.ocr; import java.util.hashmap;import java.util.map;import net.sf.json.jsonobject;import org.apache.commons.httpclient.httpstatus;import org.apache.http.httpentity;import org.apache.http.httpresponse;import org.apache.http.statusline;import org.apache.http.client.httpclient;import org.apache.http.client.methods.httppost;import org.apache.http.entity.stringentity;import org.apache.http.impl.client.defaulthttpclient;import org.apache.http.params.coreconnectionpnames;import org.apache.http.util.entityutils;import weaver.general.basebean;import weaver.general.util;public class ocrclient{ private static string config_file = "ocr_tencent"; private static string host; private static int appid; private static string secretid; private static string secretkey; private static string targeturl; private static string encoding = "utf-8"; static { basebean bb = new basebean(); host = bb.getpropvalue(config_file, "host"); appid = util.getintvalue(bb.getpropvalue(config_file, "appid")); secretid = bb.getpropvalue(config_file, "secretid"); secretkey = bb.getpropvalue(config_file, "secretkey"); targeturl = bb.getpropvalue(config_file, "targeturl"); } /** * 識別圖片 * @param imageurl * @param paramsmap 參數map * @return * @throws exception */ public static map<string, object> recognizeimage(map<string,object> paramsmap) throws exception{ httpclient httpclient = new defaulthttpclient(); httppost httppost = new httppost(targeturl);// 創建httppost httppost.setheader("host", host); //設置簽名 httppost.setheader("authorization", signutil.appsign(appid, secretid, secretkey, "", 2592000));//設置請求頭, 簽名 //設置參數 jsonobject requestparam = new jsonobject(); requestparam.put("appid", string.valueof(appid)); for(string key :paramsmap.keyset()){//循環加入請求參數 requestparam.put(key, paramsmap.get(key)); } //請求報文 stringentity entity = new stringentity(requestparam.tostring(), encoding); entity.setcontentencoding(encoding); entity.setcontenttype("application/json");//發送json數據需要設置contenttype httppost.setentity(entity); httppost.getparams().setparameter(coreconnectionpnames.connection_timeout, 120000); httppost.getparams().setparameter(coreconnectionpnames.so_timeout, 120000); int state = 0; string result = ""; httpresponse response = null; try { response = httpclient.execute(httppost); statusline status = response.getstatusline(); state = status.getstatuscode(); if (state == httpstatus.sc_ok) { httpentity responseentity = response.getentity(); result = entityutils.tostring(responseentity); }else{ //new basebean().writelog("讀取ocr駕駛證或者行駛證接口失敗，狀態碼:"+state); } } finally { httpclient.getconnectionmanager().shutdown(); } map<string, object> resultmap = new hashmap<string, object>(); resultmap.put("state", state); resultmap.put("result", result); return resultmap; } //測試 public static void main(string[] args) { string imgurl = "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1532414063478&di=f8709d73023a1a4ef9fe58f23ec95a8e&imgtype=jpg&src=http%3a%2f%2fimg3.imgtn.bdimg.com%2fit%2fu%3d2587099383%2c4041264664%26fm%3d214%26gp%3d0.jpg"; try { //車牌號識別參數設置 map<string, object> requestparam = new hashmap<string, object>(); requestparam.put("url", imgurl); map<string,object> res =recognizeimage(requestparam); //解析車牌號返回值 jsonobject resultjson = jsonobject.fromobject(res.get("result")); system.out.println(resultjson.tostring()); } catch (exception e) { e.printstacktrace(); } }} |
如需調用其他接口，如身份證識別接口、駕駛證識別接口、等，則只需要修改一下配置文件的targeturl，并且調用時傳入相應的參數即可。
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持服務器之家。
原文鏈接：https://blog.csdn.net/qq_21134557/article/details/81363227
