I am using web3j and Geth and created a private network. However, I want to do the mining manually whenever required, since don't want to jam the server when I am in the development phase. For that, I found JsonRpc2_0Geth update in web3j and used it. However, mining does not start. Please help me where I am going wrong.



Then, i called the Geth aPI through my java file as follows:

static public Web3j web3j = Web3j.build(new HttpService("<geth ip>:<port>"));
static public JsonRpc2_0Geth geth = new JsonRpc2_0Geth(new HttpService("<geth ip>:<port>"));
  • geth.minerStart(1000); asks miner to use 1000 threads, you can try following troubleshooting. 1. Try 1 thread geth.minetStart(1) and try start mining from console. Do any of these work ? Commented Dec 5, 2018 at 3:38
  • mining from geth console works. Not from the java file though. How can i troubleshoot for java ? Commented Dec 5, 2018 at 4:16
  • Does it work with geth.minerStart(1) Commented Dec 5, 2018 at 4:19
  • And what is the full command line that is used to start geth ? Commented Dec 5, 2018 at 4:21
  • No, geth.minerStart(1) did not work for me. The way i used it is mentioned in my original draft. The way i started geth node is : geth --port 3000 --networkid 1996 --nodiscover --datadir=./datadir --maxpeers=0 --rpc --rpcport 8585 --rpcaddr --rpccorsdomain "*" --rpcapi "eth,net,web3,personal,miner, admin, txpool" console Commented Dec 5, 2018 at 5:27

1 Answer 1


Posting to RPC URL is a way to start mining from any language


I.e. post this data to RPC URL.

Command line example is :

curl -X POST --data '{"jsonrpc":"2.0","method":"miner_start","params":[4],"id":74}' localhost:8545


This page has example of sending a POST request from Java.


  • I am trying this solution. Thanks for the response . Will update you soon. Commented Dec 6, 2018 at 4:32

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