Federal prosecutors were seeking up to 20 years for James, but the judge last week said such a long sentence was not warranted.
The 72-year-old former mayor apologized to the city and his family before sentencing. "I made a mistake. I'm a human being," he said.
"I would like to apologize to my wife of 44 years and my mother, who is 94, for the hardship and suffering they have had to endure," James told the hushed courtroom. "If I made a mistake, it was not of malice or intent."
Defense lawyers sought probation for James, who led New Jersey's largest city for 20 years. He was also a Democratic state senator.
Also sentenced Tuesday was James' former mistress, 39-year-old Tamika Riley, who got a 15-month term and was ordered to repay $27,000 for cheating on a federal housing subsidy.
Prosecutors charged that James abused his office and betrayed his constituents by arranging for the sale of nine city-owned properties for $46,000 to Riley from 2001 to 2005. Riley quickly sold them for $665,000 without ever starting required rehabilitation work on most of them, prosecutors said.
Martini ordered James and Riley to surrender by Sept. 15 to prisons that have yet to be assigned. Both are appealing their convictions.
The judge said James "has accomplished much in his life." He said the prosecution request for up to 20 years "disappoints me and shocks me," noting that James did not take any bribes, and that recent sentences for elected officials convicted of bribery were seven years or less.
U.S. Attorney Christopher Christie said he planned to ask the Justice Department for permission to appeal both sentences, saying he disagreed with the judge's reasoning.
"I don't think it makes a difference if you get bribed with money or get bribed with sex," Christie said.
Christie said he did not question the sincerity of James' apology, but said, "I think he's sorry he got caught."
The judge determined the city did not lose any money from the sales, but the prosecution contended the sentences should reflect that James gained companionship and that Riley cleared over $430,000.
"The victim here is the public trust," Martini said, adding that officials have an obligation to disclose relationships.
James lawyer Thomas Ashley said that if the mayor committed any crime, it was in failing to tell city officials of his relationship with Riley.
"This is not a case where Sharpe James sold his office," Ashley said.
The lawyer added that James accomplished great things for Newark, attracting new development and clearing slums.
Ashley maintained that Riley bought the properties for the same rate as other redevelopers, $2,000 per apartment, but prosecutors insisted she would never have been accepted to the program except for intervention by James.
Riley told the judge, "I made a lot of mistakes, but I did not come to Newark or any other city to take or defraud."
"I'm responsible for my mistakes," Riley said, and she apologized to family and James' wife.
Her lawyer, Gerald Krovatin, said, "She became a prop in a government plot writ large," adding she was caught up in a prosecution effort to destroy James.
Neither Riley nor James spoke upon leaving the courthouse following the sentencing.
Prosecutor Judith H. Germano argued that James deserved extra time because of his leadership of the conspiracy, and its seven-year duration.
James and Riley were convicted in April on all charges they faced.
James was convicted on five counts, including conspiracy and fraud. Riley, a publicist who once ran a clothing boutique near City Hall, was convicted on those and the eight other counts she faced, including tax evasion and cheating to obtain subsidized housing assistance for herself.
James had faced a second trial on charges he racked up $58,000 on city credit cards for lavish personal expenses and for travels with several women other than his wife. But prosecutors reached a deal with him in May that they would drop those charges unless any portion of his conviction is overturned; they said additional convictions would not mean much more prison time.
James was one of the most powerful figures snared in a series of corruption cases in New Jersey brought by the U.S. attorney's office, but one of the few to plead not guilty. He left office in 2006 after declining to seek a sixth term.
As a result of his conviction, James could be stripped of pensions that provide a six-figure annual income. State Treasury spokesman Tom Bell said "honorable service" reviews can start now that sentencing has occurred.
