API对接中经常会出现的签名获取，这只是某一种，仅供给有需要的人参考

要求：

1.对所有传入参数(含系统参数和接口参数)按照字段名的 ASCII 码从小到大排序（字典序）后，使用 URL 键值对的格式。（即 key1=value1&key2=value2…）拼接成字符串string1， 注意：值为空的参数不参与签名。

2.在string1后面拼接上key=privateKey得到stringSign字符串，并对stringSign进行sha1运算，再将得到的字符串转为大写，得到sign值。如对 age=12&name=张三 key=privateKey 进行 sha1 加密后得到 xxxxx。

参考代码：

public class Encrypt {
    private static Logger logger = LoggerFactory.getLogger(Encrypt.class);
    public static final String key = "12345abc";
    
    
    public static void main(String[] args) {
        
        //创建实体类
        SubmitAssetRequest submitAssetRequest = new SubmitAssetRequest();
        submitAssetRequest.setBidType("1");
        submitAssetRequest.setBankCardNo("6217002870039791536");
        submitAssetRequest.setBankName("中国建设银行");
        submitAssetRequest.setPeriodsType(1);
        submitAssetRequest.setAmount(new BigDecimal(1000));
        submitAssetRequest.setIdCardNumber("420117199105248734");
        submitAssetRequest.setMobile("18807111634");
        submitAssetRequest.setSex(1);
        submitAssetRequest.setMarriageState(0);
        submitAssetRequest.setName("张三");
        submitAssetRequest.setPeriods(14);
        submitAssetRequest.setChannelCode("NYD");
        submitAssetRequest.setRates(new BigDecimal(23.76));
        submitAssetRequest.setOrderId("101537895995716001");
        
        //参数封装到map集合
        Map<String, String> map = getMap(submitAssetRequest);
        
        //排序
        String sign = getSign(map);
        System.out.println(sign);
        
        
        
    }
    
    /**
     * 将参数封装到map集合，不为空的参数添加进去
     * @param request
     * @return
     */
    public static Map<String, String> getMap(SubmitAssetRequest request){
        Map<String, String> map = new HashMap<>();
        map.put("channelCode",request.getChannelCode());
        map.put("orderId",request.getOrderId());
        map.put("name",request.getName());

if (!StringUtils.isEmpty(request.getInvestorList())){
            map.put("investorList",request.getInvestorList());
        }

map.put("bidType",request.getBidType());
        map.put("sex",String.valueOf(request.getSex()));
        map.put("mobile",request.getMobile());
        map.put("idCardNumber",request.getIdCardNumber());
        map.put("bankName",request.getBankName());
        map.put("bankCardNo",request.getBankCardNo());

if (!StringUtils.isEmpty(request.getLoanUse())){
            map.put("loanUse",request.getLoanUse());
        }

if (request.getIncome() != null){
            map.put("income",String.valueOf(request.getIncome()));
        }

if (!StringUtils.isEmpty(request.getAddress())){
            map.put("address",request.getAddress());
        }

if (!StringUtils.isEmpty(request.getBirthPlace())){
            map.put("birthPlace",request.getBirthPlace());
        }

if (String.valueOf(request.getMarriageState()) != null){
            map.put("marriageState",String.valueOf(request.getMarriageState()));
        }

map.put("periods",String.valueOf(request.getPeriods()));
        map.put("periodsType",String.valueOf(request.getPeriodsType()));
        map.put("amount",String.valueOf(request.getAmount()));
        map.put("rates",String.valueOf(request.getRates()));

return map;
    }
    
    public static String getSign(Map<String, String> map){
        
        if (map == null || map.size() == 0) {
            return null;
        }
        
        List<String> list = new ArrayList<>();
        for (Map.Entry<String,String> entry : map.entrySet()) {
            if(entry.getValue()==null || entry.getValue().trim().length()==0){
                continue;
            }
            list.add(entry.getKey());
        }
        Collections.sort(list);
        
        logger.info("排序后的list:"+list.toString());

StringBuilder sb = new StringBuilder();
        for (String str:list){
            try {
                sb.append(str).append("=").append(URLEncoder.encode(map.get(str).toString(),"UTF-8")).append("&");
            } catch (UnsupportedEncodingException e) {
                logger.error("编码异常",e);             
            }
        }

sb.append("key=");
        sb.append(key);
        
        String ss = sb.toString();
        if (ss == null) {
            return null;        
        }
        String result = DigestUtils.sha1Hex(ss.getBytes());
        logger.info("最终结果:"+result);
        //转为大写
        String upperCase = result.toUpperCase();
        return upperCase;
        
    }
    
    
    
}

//对应实体类

public class SubmitAssetRequest {
     //渠道号
    private String channelCode;

//订单号
    private String orderId;

//姓名
    private String name;

//投资人列表(非必传)
    private String investorList;

//标的类型    1:定向标 2:非定向标
    private String bidType;

//性别   1:表示男性    2:表示女性
    private int sex;

//手机号
    private String mobile;

//身份证号
    private String idCardNumber;

//银行名称
    private String bankName;

//银行卡号
    private String bankCardNo;

//借款用途(非必传)
    private String loanUse;

//收入(非必传)
    private String income;

//住址(非必传)
    private String address;

//户籍地址(非必传)
    private String birthPlace;

//婚姻状况(非必传)     0 未婚 1 已婚
    private int marriageState;

//借款期限   =1 时，表示天;  =2 时，表示期
    private int periods;

//期限类型     1 表示单期 ;  2 表示多期
    private int periodsType;

//借款金额
    private BigDecimal amount;

//借款利率
    private BigDecimal rates;

//签名
    private String sign;

public String getChannelCode() {
        return channelCode;
    }

public void setChannelCode(String channelCode) {
        this.channelCode = channelCode;
    }

public String getOrderId() {
        return orderId;
    }

public void setOrderId(String orderId) {
        this.orderId = orderId;
    }

public String getName() {
        return name;
    }

public void setName(String name) {
        this.name = name;
    }

public String getInvestorList() {
        return investorList;
    }

public void setInvestorList(String investorList) {
        this.investorList = investorList;
    }

public String getBidType() {
        return bidType;
    }

public void setBidType(String bidType) {
        this.bidType = bidType;
    }

public int getSex() {
        return sex;
    }

public void setSex(int sex) {
        this.sex = sex;
    }

public String getMobile() {
        return mobile;
    }

public void setMobile(String mobile) {
        this.mobile = mobile;
    }

public String getIdCardNumber() {
        return idCardNumber;
    }

public void setIdCardNumber(String idCardNumber) {
        this.idCardNumber = idCardNumber;
    }

public String getBankName() {
        return bankName;
    }

public void setBankName(String bankName) {
        this.bankName = bankName;
    }

public String getBankCardNo() {
        return bankCardNo;
    }

public void setBankCardNo(String bankCardNo) {
        this.bankCardNo = bankCardNo;
    }

public String getLoanUse() {
        return loanUse;
    }

public void setLoanUse(String loanUse) {
        this.loanUse = loanUse;
    }

public String getIncome() {
        return income;
    }

public void setIncome(String income) {
        this.income = income;
    }

public String getAddress() {
        return address;
    }

public void setAddress(String address) {
        this.address = address;
    }

public String getBirthPlace() {
        return birthPlace;
    }

public void setBirthPlace(String birthPlace) {
        this.birthPlace = birthPlace;
    }

public int getMarriageState() {
        return marriageState;
    }

public void setMarriageState(int marriageState) {
        this.marriageState = marriageState;
    }

public int getPeriods() {
        return periods;
    }

public void setPeriods(int periods) {
        this.periods = periods;
    }

public int getPeriodsType() {
        return periodsType;
    }

public void setPeriodsType(int periodsType) {
        this.periodsType = periodsType;
    }

public BigDecimal getAmount() {
        return amount;
    }

public void setAmount(BigDecimal amount) {
        this.amount = amount;
    }

public BigDecimal getRates() {
        return rates;
    }

public void setRates(BigDecimal rates) {
        this.rates = rates;
    }

public String getSign() {
        return sign;
    }

public void setSign(String sign) {
        this.sign = sign;
    }

}