The purpose of this study is to evaluate the safety of JNJ-42847922 following single oral administration.

This is a single center, double-blind (neither the researchers nor the participants know what treatment the participant is receiving), placebo-controlled (an inactive substance; a pretend treatment [with no drug in it] that is compared in a clinical trial with a drug to test if the drug has a real effect), randomized (study medication assigned to participants by chance), single-ascending dose study. The study consists of a screening phase, an in-clinic treatment phase, and a follow-up phase. The study duration for each subject will be approximately 5 weeks from screening (Day -28 to Day -3), in-clinic period (Day -2 to Day 4) to follow up visit (Day 8). Participants will receive a single oral dose of JNJ-42847922 or placebo in 3 cohorts. Participants' safety will be monitored throughout the study.

Inclusion Criteria:

• Participant must be willing and able to adhere to the prohibitions and restrictions specified inprotocol, Prohibitions and Restrictions
• A man who is sexually active with a woman of childbearing potential and has not had avasectomy must agree to use an adequate contraception method as deemed appropriate by the investigator (eg, vasectomy, double-barrier, partner using effective contraception), and all men must also agree not to donate sperm during the study and for 3 months afterreceiving the last dose of study drug
• Participant must have a body mass index (BMI) between 18.0 and 29.9 kilogram per square meter (kg/m^2), and body weight not less than 50 kg
• Participant must have a 12-lead electrocardiogram (ECG) consistent with normal cardiac conduction and function, Including: Synus rhythm; Heart rate between 45 and 99 beats per minute (bpm); QT corrected according to Fridericia's formula (QTcF) interval less than or equal to (<=)450 milliseconds (ms); QRS interval of <=120 ms; PR interval <=220 ms; Morphology consistent with healthy cardiac conduction and function
• Nonsmoker (not smoked for 3 months prior to screening)

Exclusion Criteria:

• Participant has a history of or current clinically significant medical illness including (but notlimited to) cardiac arrhythmias or other cardiac disease, hematologic disease, coagulationdisorders (including any abnormal bleeding or blood dyscrasias), lipid abnormalities,significant pulmonary disease, including bronchospastic respiratory disease, diabetesmellitus, hepatic or renal insufficiency, thyroid disease, neurologic or psychiatric disease,infection, or any other illness that the investigator considers should exclude the participant orthat could interfere with the interpretation of the study results
• Participant has a clinically significant abnormal value for hematology, coagulation,biochemistry, or urinalysis at screening as deemed appropriate by the investigator
• Participant has a clinically significant abnormal physical examination, neurologic examination,or vital signs as deemed appropriate by the investigator
• Use of any prescription or nonprescription medication (including vitamins and herbalsupplements), except for acetaminophen within 14 days before study drug administration onDay 1
• Participant has known allergies, hypersensitivity, or intolerance to JNJ-42847922 or its excipients