http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); _> |R-vQ8
} V:F+HMBk
for(int i=0;i<nEndPos.length-1;i++) >0<KkBH
{ H7tQ#
nEndPos = nStartPos[i+1]; 93^(O8.
} o3i,B),K
nEndPos[nEndPos.length-1] = nFileLength; Xc9p;B>^Ts
} <(bCz>o|
} R%)2(\
iA%' ;V
@!&Jgg53G
//启动子线程 #lyM+.T
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K[#v(<)
for(int i=0;i<nStartPos.length;i++) Qw6KX#n
{ p-i.ITRS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uzVG q!'H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I_zk'
nStartPos,nEndPos,i); {+/ .5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -lP )
fileSplitterFetch.start(); w$b+R8.n)
} {7K'<ti
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oc3dd"8}@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @tE&<[e
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Rg8m4xw
nEndPos = " + nFileLength); s}[A4`EWH
// fileSplitterFetch[nPos.length-1].start(); 38w.sceaT
C)J_lI{^
s0\f9D
//等待子线程结束 qlz9&w
//int count = 0; ;e~{TkD
//是否结束while循环 Msv*}^>
boolean breakWhile = false; o8};e
1Es*=zg
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while(!bStop) +#-kIaU
{ ^&`sWO@=
write_nPos(); Mz/]DJ8
Utility.sleep(500); +gbX}jF0%
breakWhile = true; )p/=u@8_f
3WO#^}t
t?]\M&i&
for(int i=0;i<nStartPos.length;i++) kW<Yda<a
{ pBg|n=^
if(!fileSplitterFetch.bDownOver) b"R, p=M
{ 5#TrCPi6A
breakWhile = false; KdOh'OrT9.
break; RV0>-@/x
} z)58\rtz
} ,Lt~u_lve
if(breakWhile) .g/ARwM}
break; C@TN5?Z
{[M0y*^64$
o~OwE7H)A
//count++; '!j #X_;
//if(count>4) C=oM,[ESQ0
// siteStop(); ?qd,>
} i\kTm?BQZ
QMXD9H0{
O8K@&V p
System.err.println("文件下载结束！"); wMH[QYb<*
} Ss@u,`pr
catch(Exception e){e.printStackTrace ();} c N02roQl
} ] ?DDCew
Q(~3pt
3W7;f!
//获得文件长度 krQl^~@
public long getFileSize() <mv7HKVg
{ Je#!Wd
int nFileLength = -1; ~_DF06G
try{ /<3;0~#){
URL url = new URL(siteInfoBean.getSSiteURL()); |eHwp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g9yaNelDh)
httpConnection.setRequestProperty("User-Agent","NetFox"); Veb+^&
Lv `#zgo_f
?1GY%-
int responseCode=httpConnection.getResponseCode(); ^lHb&\X
if(responseCode>=400) Qqd6.F
{ -Z:]<;qU
processErrorCode(responseCode); /6+1{p
return -2; //-2 represent access is error w)45SZ.
} B#HV20\?v
+V)qep"
}1U#Ve,=_
String sHeader; P'a0CE%
qn2o[x
E:uReT
for(int i=1;;i++) t{/hkXq]
{ ,sO:$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ZWf-X
//Utility.log(in.readLine()); q*~gWn>T
sHeader=httpConnection.getHeaderFieldKey(i); GY oZ$p"C
if(sHeader!=null) rPRrx-A
{ !UBy%DN~k
if(sHeader.equals("Content-Length")) jP1$qhp
{ O0@w(L-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6eOrs-ty
break; mND XzT&
} NJn&>/vM
} aQ(`6DQv
else Z} c'Bm(
break; iLF^%!:X%
} uY.=4l
} l%rx#;=u
catch(IOException e){e.printStackTrace ();} cqeR<len
catch(Exception e){e.printStackTrace ();} /SnynZ.q
:|Z$3q
R;H?gE^m-
Utility.log(nFileLength); 1a<]$tZk
aRbx
lkV6qIj
return nFileLength; "e~k-\^Y
} S3SV.C:z>
;knd7SC
|J:$MX~
//保存下载信息（文件指针位置） xKY$L*
private void write_nPos() cvKV95bn
{ 1s Br.+p
try{ -u6}T!
output = new DataOutputStream(new FileOutputStream(tmpFile)); o:_^gJ+|
output.writeInt(nStartPos.length); sT)6nV
for(int i=0;i<nStartPos.length;i++) vT?Q^PTO
{ . 3GnZR,L
// output.writeLong(nPos); }c} ( 5
output.writeLong(fileSplitterFetch.nStartPos); Yx6hA#7I
output.writeLong(fileSplitterFetch.nEndPos); RXBb:f
} W@l+ciZ_
output.close(); 3@&bxYXm
} o>2e!7
catch(IOException e){e.printStackTrace ();} |</"N-#S
catch(Exception e){e.printStackTrace ();} 6G'<[gL j
} ([Ebsj
?8Et[tFg
wuKl-:S;Vs
//读取保存的下载信息（文件指针位置） mKV'jm0
private void read_nPos() 1xz\=HOT
{ `8,w[o oC2
try{ PfyRZ[3)c
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fCB:733H
int nCount = input.readInt(); w TlGJ$D0
nStartPos = new long[nCount]; sYI~dU2H
nEndPos = new long[nCount]; +)gGs#2X
for(int i=0;i<nStartPos.length;i++) Wdo#?@m
{ ,E&Bn8L~O
nStartPos = input.readLong(); u,fA!
nEndPos = input.readLong(); v51EXf
} U|8[#@r
input.close(); Xtft*Z
} 5^>n5u/
catch(IOException e){e.printStackTrace ();} _().t5<
catch(Exception e){e.printStackTrace ();} =HMmrmz:
} gC`)]*'tE
1 o|T
X:_<Y_JT
private void processErrorCode(int nErrorCode) N<(HPE};
{ s|Zx(.EP
System.err.println("Error Code : " + nErrorCode); 8zZSp
} ^;zWWg/d
[G a~%m
&eIGF1ws
//停止文件下载 m=QCG)s
public void siteStop() ,>u=gA&}
{ VpSEVd:n
bStop = true; &s:=qQa1
for(int i=0;i<nStartPos.length;i++) @;m$ua*|:
fileSplitterFetch.splitterStop(); ;`kWpM;
2/@D7>F&g
R uLvG+
} ]M3#3Ha"
} .B>B`q;B
//负责部分文件的抓取 u?kD)5Nk
**FileSplitterFetch.java W (`c
*/ 7UKYmJk.
package NetFox; *zy'#`>
8%[HYgd5)
B;!f<"a8
import java.io.*; +yWR#[`n
import java.net.*; RZO5=L9E
6Nt$ZYS
[Uli>/%JB
public class FileSplitterFetch extends Thread { TFy7HX\Oq
F6W}mMZH/N
YUscz!rM
String sURL; //File URL 2zK"*7b?
long nStartPos; //File Snippet Start Position &x0C4Kh
long nEndPos; //File Snippet End Position 9cQ_mgch
int nThreadID; //Thread's ID G;TsMq
boolean bDownOver = false; //Downing is over $}R$t-
boolean bStop = false; //Stop identical YsP/p-
FileAccessI fileAccessI = null; //File Access interface !8*McOI
Q2/.6O8
~Fw<eY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]TSg!H
{ m_*R.a
this.sURL = sURL; HM&1yubh#
this.nStartPos = nStart; MdC<4^|
this.nEndPos = nEnd; K;U39ofW
nThreadID = id; /APcL5:=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wGJjA=C
} ,+._;[k
5j eO"jB
]` ]g@v
public void run() 0@)%h&mD
{ frN3S
while(nStartPos < nEndPos && !bStop) Km3&N
{ NP/>H9Q2%
zoP%u,XL
@Z;1 g
try{ F Z!J
URL url = new URL(sURL); ++8_fgM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lJ{V
httpConnection.setRequestProperty("User-Agent","NetFox"); 1$ML#5+,
String sProperty = "bytes="+nStartPos+"-"; mJC3@V s
httpConnection.setRequestProperty("RANGE",sProperty); PJgp+u<
Utility.log(sProperty); #U=;T]!'$
)"`!AerJ
4:mCXP,x
InputStream input = httpConnection.getInputStream(); |NrrTN?>
//logResponseHead(httpConnection); <\@1Zz@ms
}B q^3?,#{
47UO*oLS
byte[] b = new byte[1024]; f:xWu-
int nRead; dvjTyX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *8)2iv4[
{ F9H~k"_ZJR
nStartPos += fileAccessI.write(b,0,nRead); (][LQ6Pc
//if(nThreadID == 1) a3@w|KLt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lj2=._@R
} 1f4bt6[
;/LD)$_
IfV 3fJ7
Utility.log("Thread " + nThreadID + " is over!"); kWL.ewTiex
bDownOver = true; GBP-V66
//nPos = fileAccessI.write (b,0,nRead); ._CP% R
} <7n]Ai@Y
catch(Exception e){e.printStackTrace ();} 1H{jy^sP7
} R$m`Z+/@
} DQJG,?e{
&mE?y%
](K0Fwo`;"
//打印回应的头信息 LJQJ\bT?
public void logResponseHead(HttpURLConnection con) Cca0](R*&
{ 2cf' ,cv@8
for(int i=1;;i++) 2~c~{ jl\
{ ?Zz'|.l@
String header=con.getHeaderFieldKey(i); [@"wd_f{l
if(header!=null) Owf.f;QR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )1F<6R
Utility.log(header+" : "+con.getHeaderField(header)); naNyGE7)
else TJy4<rb
break; }$gmK
} M>l^%`
} R,Oe$J<
{6 .o=EyM{
\cuS>G
public void splitterStop() x<B'.3y
{ Vhg1/EgUr
bStop = true; oRq!=eUu_
} 1 W'F3
oq;'eM1,.
YaY8 `M{
} {CUk1+
.T.5TMiOSq
$.K?N@(W
/* Cg!^S(U4
**FileAccess.java or_+2aG
*//文件访问(定位，写) c3xl9S,5
package NetFox; H+ZSPHs
import java.io.*; =_pwA:z"A
+=P@HfVfiq
gPEqjj
public class FileAccessI implements Serializable{ y,m2(V
H{fM%*w
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6C-YyI#s#
RandomAccessFile oSavedFile; 8_we: 9A
long nPos; (P@Y36j>N
or?%-)
X K>&$<5{
public FileAccessI() throws IOException :tGYs8UK
{ 61K"(r~
this("",0); ..KwTf
} k#)Ad*t
=-jD~rN4;P
hW2.8f$
public FileAccessI(String sName,long nPos) throws IOException &M"ouy Zo9
{ py<_HyJ
oSavedFile = new RandomAccessFile(sName,"rw"); \2X$C#8E
this.nPos = nPos; F 3RB
oSavedFile.seek(nPos); s& yk
} =mt?Cn}
CjL<RJR=
BzbDZV
public synchronized int write(byte[] b,int nStart,int nLen) ,M6ZZ* ,e
{ 4j'd3WGpbN
int n = -1; <$E6oZ
try{ faJM^u
oSavedFile.write(b,nStart,nLen); kE)!<1yy2
n = nLen; 8{I"q[GZ
} rT7^-B*
catch(IOException e) Un@\kAY
{ "{BqtU*.
e.printStackTrace (); xJ(:m<z
} aXR%;]<Dw
t[C1z
OtUrGQP
return n; (Mt5P
} w:ULi3
1B:aC|B
O!R"v'
} N:BL=}V
Dpqt;8"2L
2(#Ks's?
/* Dy9\O77>
**SiteInfoBean.java :Jxh2
*/ $\\lx_)
package NetFox; j, u#K)7{T
)pgrl
`y!/F?o+!
public class SiteInfoBean { @h?crJ6$
&a)vdlZSE=
kU*{4G|6
private String sSiteURL; //Site's URL 0Xl%uF+w
private String sFilePath; //Saved File's Path \cySWP[
private String sFileName; //Saved File's Name r|R7-HI
private int nSplitter; //Count of Splited Downloading File ;4~U,+Av
|:q/Dt@
_PXdzeI.
public SiteInfoBean() 3C^1frF
{//nSplitter的缺省值为5 FLr;`3
//default value of nSplitter is 5 _N#&psQzw
this("","","",5); vK$^y^
} 2VgP
j F5Blc
(.X]F_*sc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,E*R,'w
{ le .'pP@
sSiteURL= sURL; k`YYZt]@
sFilePath = sPath; ]n v( aM?d
sFileName = sName; tS?lB05TOR
this.nSplitter = nSpiltter; 5vOCCW
T0e<Slo~C
ST',4Oph5
} $&{IKP)u
F]=B'ZI
O6c\KFBSJ
public String getSSiteURL() 4u1KF:g
{ isK;mU?<
return sSiteURL; ~brFo2
} pB01J<@m
O!F]^'!
*"9<TSU%m
public void setSSiteURL(String value) _%pAlo_6
{ 4<v;1
sSiteURL = value; u<Xog$esu
} 's%q
_m'ysCjA
fE;Q:# Z.
public String getSFilePath() 8A2z 5Aa
{ ">90E^
return sFilePath; t1i(;|8|
} cf;Ht^M\
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uofLhy!
public void setSFilePath(String value) f(Hu {c5yV
{ h4`9Cfrq,
sFilePath = value; tYe:z:7l?<
} !]b@RUU
L* |1/
$@uU@fLB
public String getSFileName() +;gsRhWk
{ ?pwE0N^
return sFileName; ?0vNEz[
} AU{:;%.g
?U9/fl
lOerrP6f(
public void setSFileName(String value) bhg}-dto
{ 2{o10eL
sFileName = value; zhsx&
} `deYi2z
R]L2(' B
e!0OW7kV
public int getNSplitter() r6Nm!Bq7
{ r"_Y3SxxL
return nSplitter; l5J.A@0
} 8LrK94
i0Pn Z J
|B[eJq
public void setNSplitter(int nCount) ($d4:Ww
{ \ P/W8{
nSplitter = nCount; ; B$*)X9
} L.)yXuo4
} >)c9|e=8
d-$_|G+
]+%=@mWYs
/* 77aX-e*=E
**Utility.java +{-]P\oc
*/ F)ci9-b@
package NetFox; VifmZ;S@Y
MOHHZApt
J r*"V`
public class Utility { A7Y_HIo
gGfq6{9g
=/Juh7[C
public Utility() uqZ3Hyb
{ ^gg!Me
E(Gr0#8
eyB_l.U7
} {LB`)Kuu
buYDl
//线程睡眠 x_:hii?6V
public static void sleep(int nSecond) nVOqn\m-
{ v33T @
try{ J(9=T<%T
Thread.sleep(nSecond); p_6P`Yx^e
} kL;t8{n
catch(Exception e) {ymb\$f
{ r{ @ `o@q
e.printStackTrace (); (%DRt4u<H
} =K'L|QKF
} s[V`e2O
l,y^HTc}7/
//日志 <\DUo0]J
public static void log(String sMsg) GOr}/y;
{ VGJDqm!
System.err.println(sMsg); _rjBc;a
} %b<%w
Zi1YZxF`Y
AbY;H
public static void log(int sMsg) a4by^
{ SIv[9G6
System.err.println(sMsg); V9{B}5KC
} t2.juoI(
} #313 (PWH
JtmQzr0>
?>?ZAr
/* _85E=
**TestMethod.java 3yMt1 fy
*/ 2np-Fc{S
package NetFox; <^sAY P|
l $Zs~@N
J/7u7_
public class TestMethod { M?hFCt3Y
<2)v9c
Y6;@/[_
public TestMethod() cVg$dt
{ ///xx/weblogic60b2_win.exe =,E'~P
try{ a71}y;W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); me$$he
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q9q9<J7j$
SiteFileFetch fileFetch = new SiteFileFetch(bean); FB!z#Eim
fileFetch.start(); va+m9R0
} =n)#!i
catch(Exception e){e.printStackTrace ();} rgn|24x
h7RD`k:mF
P^;WB*V
} Z@nmjji
n}5x-SxS0
_w%s(dzk
public static void main(String[] args) I,9~*^$
{ !vrnoFVu
new TestMethod(); VY{,x;O`
} nOr"K;C
} -;S3|
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