Use DO SDK with Android

Java calling DO SDK requires familiarity with the use of Java JNA.

Step

1. Import the SDK

Download the source code and import it into your project to compile it into a dynamic library.

/**
* @brief      Create hexadecimal seed
* @return      jbyteArray : Hexadecimal seed
*/
JNIEXPORT jbyteArray JNICALL Java_com_example_jni_sig_newSeed
  (JNIEnv *env , jobject);


/**
* @brief      Export a hexadecimal array of private keys based on the private key
* @param       jlong : private key
* @return      jstring : Private key hexadecimal array
*/
JNIEXPORT jstring JNICALL Java_com_example_jni_sig_ExportPriHexStr
  (JNIEnv *, jobject, jlong);


/**
* @brief      Export private key based on hexadecimal array of private keys
* @param       jstring : Private key hexadecimal array
* @return      jlong : private key
*/
JNIEXPORT jlong JNICALL Java_com_example_jni_sig_ImportPriHexStr
  (JNIEnv *, jobject, jstring);


/**
* @brief    Export private key based on hexadecimal array of private keys
* @param    jbyteArray : Private key hexadecimal array
* @return   jlong : private key
*/
JNIEXPORT jlong JNICALL Java_com_example_jni_sig_importSeed
  (JNIEnv * env, jobject, jbyteArray str);


/**
* @brief     Export mnemonic words based on the hexadecimal array of seeds
* @param     jbyteArray : The hexadecimal array of seeds
* @return    jstring : Mnemonic words
*/
JNIEXPORT jstring JNICALL Java_com_example_jni_sig_ExportMnemoic
  (JNIEnv *, jobject, jbyteArray);

/**
* @brief      Export the hexadecimal array of seeds based on mnemonic words
* @param      jstring : Mnemonic words
* @return     jbyteArray : The hexadecimal array of seeds
*/
JNIEXPORT jbyteArray JNICALL Java_com_example_jni_sig_ImportMnemoic
  (JNIEnv *, jobject, jstring);


/**
* @brief      Obtain the public key base64
* @param       jlong : public  key
* @return      jstring : Public key base64
*/
JNIEXPORT jstring JNICALL Java_com_example_jni_sig_GetPubStr
  (JNIEnv *, jobject, jlong);


/**
* @brief      Obtain the public key base64
* @param       jlong pkey: public  key 
* @return      jstring : Public key base64
*/
JNIEXPORT jstring JNICALL Java_com_example_jni_sig_GetContractPubStr
 (JNIEnv *env, jobject, jlong pkey);


/**
* @brief      Obtain address based on private key
* @param       jlong : Private key 
* @return      jstring : address
*/
JNIEXPORT jstring JNICALL Java_com_example_jni_sig_GetAddr
  (JNIEnv *, jobject, jlong);


/**
* @brief      Sign the data
* @param       jlong : Private key 
* @param       jstring : Data to be signed   
* @return      jstring : Signed data
*/
JNIEXPORT jstring JNICALL Java_com_example_jni_sig_sigmessage
    (JNIEnv *, jobject, jlong, jstring);


/**
* @brief      Sign the data
* @param       jlong pkey : Private key 
* @param       jstring message :  Data to be signed 
* @return      jstring : Signed data
*/
JNIEXPORT jstring JNICALL Java_com_example_jni_sig_sigMessage
        (JNIEnv *env, jobject, jlong pkey, jstring message);


/**
* @brief      verify signature
* @param       jlong : Private key
* @param       jstring : Signed information  
* @param       jstring : Verification results
* @return      jboolean :  Verify if the signature was successful
*/
JNIEXPORT jboolean JNICALL Java_com_example_jni_sig_vefmessage
  (JNIEnv *, jobject, jlong, jstring, jstring);


/**
* @brief      Sign the `txJson` in the `result` field of the transaction return value
* @param       jlong : Private key
* @param       jstring : "txJson" information
* @return      jstring : Return the signed `txjson`
*/
JNIEXPORT jstring JNICALL Java_com_example_jni_sig_sigTx
  (JNIEnv *, jobject, jlong, jstring);


/**
* @brief      Encrypt the base64 string
* @param       jstring : The base64 string to be encrypted
* @return      jstring : Encrypted data
*/
JNIEXPORT jstring JNICALL Java_com_example_jni_sig_Base64Encode
  (JNIEnv *, jobject, jstring);


/**
* @brief      Decrypt the encrypted base64 string
* @param       jstring : The base64 string to be decrypted
* @return      jstring : Decrypted data
*/
JNIEXPORT jstring JNICALL Java_com_example_jni_sig_Base64Decode
  (JNIEnv *, jobject, jstring);


/**
* @brief      Release private key
* @param       jlong pkey : private key
*/
JNIEXPORT void JNICALL Java_com_example_jni_sig_freePrikey
        (JNIEnv *env, jobject, jlong pkey);

2. Use the SDK

Write Java code according to SDK methods.

Java use

The corresponding Java method and file directory should be consistent with the C++ method ——com_example_jni.

package com.example.jni;

public class sig {
    public native byte[] newSeed();

    public native String ExportPriHexStr(long pkey);

    public native long ImportPriHexStr(String hexStr);

    public native long importSeed(byte[] str);

    public native String ExportMnemoic(byte[] seed);

    public native long ImportMnemoic(String Mnstr);

    public native String GetPubStr(long pkey);

    public native String GetContractPubStr(long pkey);

    public native String GetAddr(long pkey);

    public native String sigmessage(long pkey, String message);

    public native String sigMessage(long pkey, String message);

    public native boolean vefmessage(long pkey, String message, String signature);

    public native String sigTx(long pkey, String tx);

    public native String Base64Encode(String str);

    public native String Base64Decode(String str);

    public native void freePrikey(long pkey);

}

Example

The following example demonstrates the generation of addresses, mnemonics, private keys, public keys, and seeds.

    /**
     * Generate account
     * @return
     */
    public static void newWallet() {
        System.loadLibrary("JNI");//
        JSONO jsonObject = new JSON();
        sig sig_obj = new sig();
        byte[] seed = sig_obj.newSeed();
        long pkey = sig_obj.importSeed(seed);
        String base58addr = sig_obj.GetAddr(pkey);
        String seedStr = sig_obj.byteArrayToHexString(seed);
        String mnemo = sig_obj.ExportMnemoic(seed);
        String pri_hex = sig_obj.ExportPriHexStr(pkey);
        String pub_hex = sig_obj.GetPubStr(pkey);
        //Account information storage
        jsonObject.put("seedStr", seedStr);
        jsonObject.put("addr", base58addr);
        jsonObject.put("mnemoni", mnemo);
        jsonObject.put("pri_hex", pri_hex);
        jsonObject.put("pub_hex", pub_hex);
    }