单例模式范例

package util;
import org.web3j.protocol.geth.Geth;
import org.web3j.protocol.http.HttpService;

public class GethClientUtil {

    private volatile static Geth geth;

    public static Geth getClient() {
        if (geth == null) {
            synchronized (GethClientUtil.class) {
                if (geth == null) {
                    try {
                        geth = Geth.build(new HttpService(PropUtil.getProps().getProperty("RPC_ADDR")));
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        }
        return geth;
    }

}

 配置文件工具类

package util;

import java.io.InputStream;
import java.util.Properties;

public class PropUtil {

    private static Properties props = null;
    
    static {
        readProperties("ether.properties");
    }
    
    private static void readProperties(String fileName) {    
        try {    
            props = new Properties();
            InputStream inputStream = Thread.currentThread().getContextClassLoader().getResourceAsStream(fileName);
            props.load(inputStream);
            inputStream.close();
        } catch (Exception e) {    
            e.printStackTrace();    
        }    
    } 
    
    public static Properties getProps() {
        return props;
    }
    
}

配置文件

#调用RPC地址
RPC_ADDR=http://127.0.0.1:8545
#矿工费参数
GAS_PRICE=22000000000
GAS_LIMIT=4300000
#私钥文件存储路径
KEYSTORE_PATH=E:/Project/TestGeth/keystore