JSON-RPC Message error when starting geth node or testrpc - json

Question

I am trying to create a private network so that I can start testing my Solidity code. However, when starting the a geth private network with geth --rpc but I then run into an error for an invalid response. {"jsonrpc":"2.0","error":{"code":-32600,"message":"EOF"}} when checking localhost:8545.
I don't think it matters, but my genesis.json file is
{
"nonce": "0x0000000000000042", "timestamp": "0x0",
"parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
"extraData": "0x0", "gasLimit": "0x8000000", "difficulty": "0x400",
"mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",
"coinbase": "0x3333333333333333333333333333333333333333", "alloc": { }}
I have also tried creating a test network with testrpc with just the command testrpc but here the localhost:8545 returns a parsing error {"jsonrpc": "2.0", "id": null, "error": {"message": "Parse error", "code": -32700}}.
What is the JSON that I am sending because it seems to be incorrectly written?
Thanks

Answer 1

It's hard to tell what exactly you are trying, but the JSON RPC endpoint of geth requires a JSON command, for instance try to query the web3 version with the following request:
{
"method": "web3_clientVersion",
"params": []
}
It complains because you do not provide any request, i.e., running a plain testrpc command.
But inbetween the lines I read that you are testing your solidity code. Have you had a look at the wonderful browser solidity?