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)); ~_ 8X%uty
} *QIlh""6
for(int i=0;i<nEndPos.length-1;i++) b,8\i|*!f
{ k[`9RGT
nEndPos = nStartPos[i+1]; ?Bdhn{_
} )M!6y%b67
nEndPos[nEndPos.length-1] = nFileLength; M'n2j
} _=wu>h&7
} yyj?hR@rZ
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DLWG0$#!
//启动子线程 i Sm .E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O_M2Axm
for(int i=0;i<nStartPos.length;i++) +p%!G1Yz
{ h "MiD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;!ICLkc$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7H+IW4Ma
nStartPos,nEndPos,i); KXQ &u{[<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'nrXRDb
fileSplitterFetch.start(); N}j]S{j}'
} 5 +Ei!E89
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~^{jfHTlv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X4c|*U=4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R-~ZvVw7L
nEndPos = " + nFileLength); '\MYC8"
// fileSplitterFetch[nPos.length-1].start(); $y0[AB|V
Em%0C@C
_{]\} =@
//等待子线程结束 nD8 Qeem@
//int count = 0; 4Pbuv6`RK
//是否结束while循环 ;77#$H8)
boolean breakWhile = false; <?Z[X{
Hd/|f;
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while(!bStop) s#8mD!T|
{ $:7T
write_nPos(); '@ $L}C#OI
Utility.sleep(500); BrHw02G
breakWhile = true; Q|DVB
0bR)]"K
e2~$=f-
for(int i=0;i<nStartPos.length;i++) R;G"LT
{ 8l?mNapy
if(!fileSplitterFetch.bDownOver) StuQ}
{ nRE(RbRe
breakWhile = false; m=qEQy6#2u
break; <r@w`G
} u{6b>c|,X
} !T'`L{Sj
if(breakWhile) R/_bk7o]H
break; ;*H@E(g
x%hV5KW
T4M"s;::1
//count++; XY_zFF
//if(count>4) Z7="on4
// siteStop(); JB <GV-l
} 1(q&(p
SJ4+s4!l <
nT;Rwz$3
System.err.println("文件下载结束！"); @X|Mguq5
} K&\ q6bU
catch(Exception e){e.printStackTrace ();} RZ6[+Ygn
} #[uDVCM
'[Ue0r<jn
dr[sSBTY"
//获得文件长度 9GV1@'<Y]
public long getFileSize() c)b/"
{ ,Vc>'4E-
int nFileLength = -1; 9tMaOm
try{ YUGEGXw
URL url = new URL(siteInfoBean.getSSiteURL()); YV{^2)^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G[bWjw86O
httpConnection.setRequestProperty("User-Agent","NetFox"); ]RvFn~E!s
x}tg/`.=z
ev{;}2~V
int responseCode=httpConnection.getResponseCode(); &c|3v!
if(responseCode>=400) j6JK4{
{ -K@mjN
processErrorCode(responseCode); F%]ZyO9
return -2; //-2 represent access is error C)a;zU;9
} B&M-em=
AW R
u alpm#GU
String sHeader; &>xd6-
M SnRx*-
}g9g]\.!a
for(int i=1;;i++) #H5i$ o
{ }#<mK3MBe
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?=dp]E{
//Utility.log(in.readLine()); Rt9S
sHeader=httpConnection.getHeaderFieldKey(i); `q$a p$?
if(sHeader!=null) *M]@}'N
{ JG:li} N
if(sHeader.equals("Content-Length")) O u-/dE%
{ HPus/#j'+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l(<=JUO;
break; n$u@v(I
} =>LQW;Sjz
} J6C/`)+w
else ;S5J"1)O~
break; nkxv,_)ZT
} 11g_!X -g@
} KB$SB25m
catch(IOException e){e.printStackTrace ();} "T4buTXJ
catch(Exception e){e.printStackTrace ();} 0|=,!sY
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N fBH
Utility.log(nFileLength); }HKt{k&$
^D5+S`V
5@-[[ $dk
return nFileLength; xo.k:F
} GD-cP5$
!SPu9:
TCLXO0
//保存下载信息（文件指针位置） WcOnv'l,
private void write_nPos() Klj -dz
{ 7@NV|Idtd
try{ &~K4I
output = new DataOutputStream(new FileOutputStream(tmpFile)); >|1$Pv?
output.writeInt(nStartPos.length); ]/6i#fTw
for(int i=0;i<nStartPos.length;i++) 4Nl3"@<$
{ kc7,F2=F
// output.writeLong(nPos); Iy#=Nq=
output.writeLong(fileSplitterFetch.nStartPos); o FS2*u
output.writeLong(fileSplitterFetch.nEndPos); L&,&SDr
} )jPIBzMys
output.close(); 9-"!v0['
} $}8@?>-w
catch(IOException e){e.printStackTrace ();} xS+!/pBf"Y
catch(Exception e){e.printStackTrace ();} k~XDwmt;
} % 4Gt^:J"
:LxsiDrF[
wM1&_%N
//读取保存的下载信息（文件指针位置） 1'YUK"i
private void read_nPos() .2{*>Dzi
{ `V2doV)
try{ ufn%sA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vI20G89E
int nCount = input.readInt(); {WvYb,
nStartPos = new long[nCount]; ;Xl {m`E+
nEndPos = new long[nCount]; ,v#O{ma
for(int i=0;i<nStartPos.length;i++) cb5T-'hY
{ Sfa;;7W@R
nStartPos = input.readLong(); u10;qYfL8o
nEndPos = input.readLong(); Tvl"KVGm
} vyvb-oz;u
input.close(); 0WSOA[R%[b
} GMlJM
catch(IOException e){e.printStackTrace ();} &>xz
catch(Exception e){e.printStackTrace ();} qH4+iSTnV
} ^6QzaC3
va2FgW`Bd+
+Kp8X53
private void processErrorCode(int nErrorCode) ~~3*o
{ 6F_:,b^
System.err.println("Error Code : " + nErrorCode); pnTz.)'46
} (tCBbPW6T?
/V }Z,'+
'<U4D
//停止文件下载 v,!`A!{D
public void siteStop() [D"5@
{ CT/>x3o
bStop = true; ct@3]
for(int i=0;i<nStartPos.length;i++) VA@
fileSplitterFetch.splitterStop(); #y f
88VI _<
Pa'N)s<
} zeD=-3
} AquO#A[,#
//负责部分文件的抓取 Gi\Z"MiBZ
**FileSplitterFetch.java 0|kH0c,T-
*/ =&^tfD
package NetFox; L]q%;u]8!
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`{NbMc\ ]
import java.io.*; n}C0gt-
import java.net.*; Wf~PP;
Ya}}a
uR.`8s|
public class FileSplitterFetch extends Thread { .O SQ8W}
-EE}HUP)
p)?6~\F:
String sURL; //File URL ,/"0tP&_;
long nStartPos; //File Snippet Start Position *xN?5u%
long nEndPos; //File Snippet End Position :o:Z
int nThreadID; //Thread's ID :jJ0 +Q
boolean bDownOver = false; //Downing is over Z4g<Ys*
boolean bStop = false; //Stop identical >`<qa!9
FileAccessI fileAccessI = null; //File Access interface = toU?:.
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TAq[g|N-;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wScr:o+K>L
{ -"I9`
this.sURL = sURL; -XnOj2
this.nStartPos = nStart; 5lyHg{iqD
this.nEndPos = nEnd; >3}N;
nThreadID = id; l5D4?`|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6Ilj7m*
} PAH#yM2Ic
n]t3d
6n;? :./
public void run() :\C/mT3xL)
{ gGx<k3W^
while(nStartPos < nEndPos && !bStop) 30<_`
{ Gzwb<e y
`|PhXr
7X>*B~(R
try{ ],{M``]q
URL url = new URL(sURL); 79I"F'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AmQsay#I_
httpConnection.setRequestProperty("User-Agent","NetFox"); t>x!CNb'C
String sProperty = "bytes="+nStartPos+"-"; ,!X:wY}dW
httpConnection.setRequestProperty("RANGE",sProperty); 5H,(\Xd
Utility.log(sProperty); E(&zH;?_
"'XYW\bI
a-AA$U9hj
InputStream input = httpConnection.getInputStream(); ~6+Um_A_L
//logResponseHead(httpConnection); u$X =2u:P
JSx[V<7m
q29d=
byte[] b = new byte[1024]; Cq3Au%7
int nRead; @Fzw_qr M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r?dkE=B
{ rV2>;FG
nStartPos += fileAccessI.write(b,0,nRead); F5OQM?J
//if(nThreadID == 1) T!Lv%i*|Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L">m2/ HG
} C =B a|Z
[{#n?BT
T5}5uk9
Utility.log("Thread " + nThreadID + " is over!"); +n)bWB%
bDownOver = true; bJkFCI/
//nPos = fileAccessI.write (b,0,nRead); b@sq}8YD|z
} GaV OMT
catch(Exception e){e.printStackTrace ();} ?}S!8;d
} -y[y.#o
} |tz{Es<`B
<p+7,aE_
Mc,p]{<<AV
//打印回应的头信息 Xn5LrLM&
public void logResponseHead(HttpURLConnection con) #a'CoJs
{ 9*Fc+/
for(int i=1;;i++) dj}P|v/;z
{ uKB V`I
String header=con.getHeaderFieldKey(i); 85Kf>z::c
if(header!=null) lE*.9T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )}vUYTU1
Utility.log(header+" : "+con.getHeaderField(header)); ey\(*Tu9
else ?%/*F<UVQ
break; T+FlN-iy)
} 23opaX5V=
} =/4}!B/
+eop4 |Z
:U]Pm:ivTU
public void splitterStop() W9bpKmc
{ q^~w:$^U
bStop = true; a)6?:nY$
} C\|HN=2eh
z^y -A?
=,&{ &m)
} L:jv%;DM
kq(]7jU$[
Bma.Uln
/* ZJ[p7XP
**FileAccess.java #jg3Ku;Y
*//文件访问(定位，写) HDz"i
package NetFox; `[x'EJp#
import java.io.*; zCu+Oi6
[kPl7[OL
_cJ\A0h^
public class FileAccessI implements Serializable{ (D\`:1g
59?$9}ob
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8P2_/)|
RandomAccessFile oSavedFile; -or)NE
long nPos; j3>&Su>H4
0iz\<' p
8{Vt8>4
public FileAccessI() throws IOException e C&!yY2g
{ SWNT}{x]
this("",0); \x"BgLSE
} YCyh+%Q(
|;YDRI
cOP%R_ak?
public FileAccessI(String sName,long nPos) throws IOException e^hI[LbNC
{ ,LL=b-Es
oSavedFile = new RandomAccessFile(sName,"rw"); w}x&wWM
this.nPos = nPos; ]YB,K)WQ
oSavedFile.seek(nPos); @rr\Jf""z
} i\RB KF
2JHV*/Q
Qr~yHFc1y
public synchronized int write(byte[] b,int nStart,int nLen) rwAycW7
{ 5"Y:^_8
int n = -1; ?6:e%YT
try{ EsLtC5]
oSavedFile.write(b,nStart,nLen); @EH@_EwYV
n = nLen; =8DS~J{
} S#\Cyn2(t
catch(IOException e) DWU(ld:_
{ F4g3l
e.printStackTrace (); f5.Be%
} ,){WK|_
E|=]k
qnw8#!%I
return n; H`T}k+e2-N
} x|3G}[=
qvRs1yr?q
e:6mz\J
} P)UpUMt;k
CrX1qyR
ABhQ7 x|
/* ='HLA-uT
**SiteInfoBean.java <J^94-[CF
*/ R78lV-};Q
package NetFox; QQUZneIDp
49 1 1
-M`+hVs?
public class SiteInfoBean { qWI8 >my11
/Fp@j/50
|TuFx=~5v
private String sSiteURL; //Site's URL R"e533
private String sFilePath; //Saved File's Path oF5~|&C
private String sFileName; //Saved File's Name <GoZ>
private int nSplitter; //Count of Splited Downloading File wmit>69S
D}bCMN<
]U5/!e
public SiteInfoBean() e:=+~F(f
{//nSplitter的缺省值为5 E^V4O l<
//default value of nSplitter is 5 :"Kr-Hm`
this("","","",5); $`Aps7A
} k)S'@>n{u
O)}5`0@L
?,*KAGg%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9H~OC8R:
{ [u/Wh+
sSiteURL= sURL; l~GcD
sFilePath = sPath; `HsI)RmX
sFileName = sName; IL<@UWs6
this.nSplitter = nSpiltter; @%$<,$=
<0H^2ekd
uJL[m(G
} }<G#bh6;Q
(/Dr=D{ `
jftf]n&Z(q
public String getSSiteURL() %ZJ;>a#
{ lNqF@eCT9
return sSiteURL; RL1cx|
} Xh"8uJD
EB[B0e7}
J, vEZT<Mt
public void setSSiteURL(String value) +:m'
{ !"N-To-c
sSiteURL = value; NEX{vZkgw
} @#&y
,$;pLjo6
u6~/" _FwY
public String getSFilePath() Y%)@)$sK
{ ffS]%qa
return sFilePath; 5j-?Uf
} ?DKwKt
p*"H&xA@
Ra^GbT|Z
public void setSFilePath(String value) by0M(h
{ Kv-4VWh
sFilePath = value; =aE!y5
} ayoqitXD?
m8<l2O=m
h;2n2.Q
public String getSFileName() TSAVXng
{ $&[}+??
return sFileName; UBvea(z-#
} ;]xJC j
w-9fskd6e
uGH>|V9'c
public void setSFileName(String value) eNw9"X}g
{ 7Q3a0`Iq
sFileName = value; \1b!I)T9
} bClMM
ZF6?N?t}h8
$d_%7xx
public int getNSplitter() T`.RP&2/d
{ ]Sgc42hk
return nSplitter; 0413K_
} Pf?y!dK<
ts3BmfR?
Auz.wes
public void setNSplitter(int nCount) \5s#9
{ dwAFJhgh
nSplitter = nCount; U$5 lh
} ^%pM$3ov
} ^q=D!g
8Qt'Y9|
:;(zA_-
/* dJ}E,rW}
**Utility.java ApxGrCu
*/ ow{SsX
package NetFox; u!VAAX
` kG}NJf
1^4z/<ZWm
public class Utility { {2Jn#&Z29
5VG[FY6Pl
9OnH3
public Utility() v2uyn
{ <p74U( V
SuU_psF
-0/5!
} l].Gz`L
oSOO5dk:z
//线程睡眠 #gL$~.1
public static void sleep(int nSecond) "/&_B
{ wtY*{m2
try{ 9j;L-
Thread.sleep(nSecond); |E YJbL;1%
} x!08FL)
catch(Exception e) RS>;$O_(M
{ A1A/OU<Vb
e.printStackTrace (); Gw5j6
} $\ 0d9^)&
} !6UtwCVR
5D32d1A
//日志 ktILKpHt"
public static void log(String sMsg) dDAIfe2y
{ 1UHStR
System.err.println(sMsg); u&!QP4$"z
} v&NC` dVR
Gqz<;y
,(6U3W*bu
public static void log(int sMsg) wK_I"
{ %6vf~oG
System.err.println(sMsg); 7eh<>X!TX
} 1,tM
} /"Bm1
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){PL6|5x
/* \UdHN=A&
**TestMethod.java 8e`'Ox_5a
*/ gRk%ObJGqm
package NetFox; *<PQp
G/2| *H
3=reN6Q
public class TestMethod { 5w\>Whbd
-gWqq7O
meHnT9a^
public TestMethod() D]H@Sx
{ ///xx/weblogic60b2_win.exe :Kl~hzVSOa
try{ ~i4h.ZLj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); FZW)C'j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); G\y:O9(
SiteFileFetch fileFetch = new SiteFileFetch(bean); ],lrT0_cT
fileFetch.start(); ^r u1QDT
} oJcDs-!
catch(Exception e){e.printStackTrace ();} #bqc}h9
_Ra$"j
Rn(vG-xQ
} yEnurq%J
t8Sblgq
:|s!_G<
public static void main(String[] args) >IL[eiiPG
{ \"]vSx>
new TestMethod(); v&hQ;v
} ZeUA e
} U#I8Rd I,
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