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)); %+y92'GqG/
} N))G/m3
for(int i=0;i<nEndPos.length-1;i++) aybfBC
{ H)${"
nEndPos = nStartPos[i+1]; %O< qw
} 6*:mc
nEndPos[nEndPos.length-1] = nFileLength; N){/#3
} sP+ZE>7
} l]GUQcN=
?z2k74&M^
Rf~? u)h1
//启动子线程 oq>8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X~Yj#@
for(int i=0;i<nStartPos.length;i++) 'Wn2+pd
{ @]EJbiGv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6,*o;<k[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iB:](Md'r
nStartPos,nEndPos,i); kZsat4r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }8W5m(Zq9n
fileSplitterFetch.start(); S1R:/9 z
} nDhD"rc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]} + NT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); '{t&!M`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #!WD1a?L
nEndPos = " + nFileLength); AxOn~fZ!
// fileSplitterFetch[nPos.length-1].start(); hu G]kv3F:
1gZW~6a}
*k]izWsV*
//等待子线程结束 e uF@SS
//int count = 0; ,/qS1W(
//是否结束while循环 D\Nhq Vw
boolean breakWhile = false; A{!D7kwTz~
;DkX"X+
Y;L,}/[
while(!bStop) .\?)O+J!
{ *c[X{
write_nPos(); Wn9b</tf
Utility.sleep(500); +])St3h
breakWhile = true; 42Gv]X
sKkk+-J4
TzCNY@y
for(int i=0;i<nStartPos.length;i++) !H5r+%Oo|
{ m 8Q[+_:$H
if(!fileSplitterFetch.bDownOver) V ?10O
{ zdwr5k
breakWhile = false; !]W}I
break; c&Mci"nj0
} 4;*o}E
} Mpm#a0f
if(breakWhile) &s|&cT
break; g]=w_
X\I"%6$
Y+k)d^6r
//count++; SLa\F
//if(count>4) pMB~Lt9
// siteStop(); v\Y362Xv
} QT5,_+ho
\`|*i$
tr]=q9
System.err.println("文件下载结束！"); Tn~b#-0
} e7j30Iy
catch(Exception e){e.printStackTrace ();} _$+lyea
} Vp;^_,
`dH[&=S
;xnJ+$//U
//获得文件长度 %n3lm(-0U
public long getFileSize() L{hP&8$k
{ >g+ogwZ
int nFileLength = -1; g,5r)FU`
try{ n]/7UH}(<&
URL url = new URL(siteInfoBean.getSSiteURL()); nyZUf{:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tFvc~zz9
httpConnection.setRequestProperty("User-Agent","NetFox"); Ip/_uDi+!Z
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int responseCode=httpConnection.getResponseCode(); MCOz-8@|Y
if(responseCode>=400) QMGMXa
{ n\Z&sc
processErrorCode(responseCode); .=WsB@+
return -2; //-2 represent access is error pPUv8, %
} 6.z8!4fpl
niZ/yW{w
=?U"#a
String sHeader; p{knQ],
C3Mr)
$z-zscco
for(int i=1;;i++) "o +" Jd
{ 6vVx>hFJ47
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bgW=.s
//Utility.log(in.readLine()); $V$|"KRcs
sHeader=httpConnection.getHeaderFieldKey(i); %4:tRF
if(sHeader!=null) A^PCI*SN[
{ 8~QEJW$
if(sHeader.equals("Content-Length")) #P,mZ}G\
{ *R17 KMS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2QUZAV\ Y
break; eGrC0[SH
} >gAq/'.Q
} KmoPFlw
else Xg|_
break; s2t'jIB
} gf`uC0
} ;<Dou7=
catch(IOException e){e.printStackTrace ();} =]h5RC
catch(Exception e){e.printStackTrace ();} m^dKww
R v61*F4
Py$*c
Utility.log(nFileLength); OO.. Y
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!br0s(|
return nFileLength; \~4uEk"]
} -DwqoWZ
z= pb<Y@X
' bio:1
//保存下载信息（文件指针位置） Fx']kn9
private void write_nPos() e-;$Iv
{ WDr'w'
try{ yZ t}Jnv
output = new DataOutputStream(new FileOutputStream(tmpFile)); X%7Y\|
output.writeInt(nStartPos.length); OHeVm-VC
for(int i=0;i<nStartPos.length;i++) /[YH W]
{ M9{?gM9
// output.writeLong(nPos); b?-Ep?G'\
output.writeLong(fileSplitterFetch.nStartPos); )>q.!"B
output.writeLong(fileSplitterFetch.nEndPos); 7_ g}t!b`
} 8=x{>&Jr&#
output.close(); D T^3K5
} Ilvz@=
catch(IOException e){e.printStackTrace ();} _K{hq<g
catch(Exception e){e.printStackTrace ();} %of#VSk
} ;+XiDEX0}
:_YpSw<Q
:UmY|=v?t
//读取保存的下载信息（文件指针位置） wXf_2qB9
private void read_nPos() y?W8FL
{ Hw8`/'M=%5
try{ ]Lq9Ompf(t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }YHoWYR
int nCount = input.readInt(); ~JY<DW7
nStartPos = new long[nCount]; Wbc*x
nEndPos = new long[nCount]; P`wp`HI
for(int i=0;i<nStartPos.length;i++) ou6|;*>d
{ v|~ yIywf
nStartPos = input.readLong(); 5DKR1z:
nEndPos = input.readLong(); IGs!SXclCs
} RWf4Wh?d
input.close(); eX$P k:
} zRsG$)B
catch(IOException e){e.printStackTrace ();} )6dvWK
catch(Exception e){e.printStackTrace ();} dL5u-<y&
} <\@JbL*
`V[{(&?,n
:i+Tf~k{
private void processErrorCode(int nErrorCode) rWI6L3,i+
{ $d.UF!s
System.err.println("Error Code : " + nErrorCode); *b9=&:pU(
} E`.dU<8HE
z>+@pj
\M1-
//停止文件下载 Fn4i[|W42
public void siteStop() i[A$K~f
{ !q!.OQ
bStop = true; e>1z1Q;_uv
for(int i=0;i<nStartPos.length;i++) "#^11o8
fileSplitterFetch.splitterStop(); A?'Tigi
bCHA!zO
~=i9]%g?
} ~7T]l1]W%
} 1i:l
//负责部分文件的抓取 Js[dT|>.
**FileSplitterFetch.java LDHuf<`
*/ JX@/rXFY}
package NetFox; 37Vs9w
`~QS3zq
PvX>+y5
import java.io.*; WjtmV2b<7
import java.net.*; w$4fS
Mp9wYM*
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public class FileSplitterFetch extends Thread { EQXvEJ^
$NzD&b$7
,-#8/9ts
String sURL; //File URL B$"CoLC7+
long nStartPos; //File Snippet Start Position F?xbVN
long nEndPos; //File Snippet End Position _U;z@
int nThreadID; //Thread's ID >p Y0f }
boolean bDownOver = false; //Downing is over 9m MPkgc
boolean bStop = false; //Stop identical ^2}0lP|
FileAccessI fileAccessI = null; //File Access interface H->J.5~,K
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [f,; +Ze
{ ZW n j-
this.sURL = sURL; ,cD(s(6+
this.nStartPos = nStart; sA=WU(4^
this.nEndPos = nEnd; E c[-@5x
nThreadID = id; LO0<=4iN(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0L1NZY^!
} |u{NM1,
B B*]" gT
1>bG]l1//
public void run() CEjMHP$=
{ &OD)e@Tc
while(nStartPos < nEndPos && !bStop) E!w%oTx{OR
{ `''\FPhh
V(n7hpS
qB PUB(
try{ ,,vl+Z<&
URL url = new URL(sURL); YNV4w{>FD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qV2aa9p+
httpConnection.setRequestProperty("User-Agent","NetFox"); B*#lkMr
String sProperty = "bytes="+nStartPos+"-"; t=\y|Idc
httpConnection.setRequestProperty("RANGE",sProperty); d[(KgX9
Utility.log(sProperty); 2.6%?E]
57*`y'CW
/ghXI"ChI
InputStream input = httpConnection.getInputStream(); ]Z%9l(
//logResponseHead(httpConnection); L5 ~wX
z)N8#Y~vn
R:8\z0"L*
byte[] b = new byte[1024]; W=j
int nRead; H.#<&5f
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,tBb$T)7<
{ v;4l*)$)
nStartPos += fileAccessI.write(b,0,nRead); #wn`choT'
//if(nThreadID == 1) Obwj=_+upd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f/Cf2 K
} Tov!X8p
S{_i1'
V4kt&61
Utility.log("Thread " + nThreadID + " is over!"); iQs7Ly"
bDownOver = true; AB92R/
//nPos = fileAccessI.write (b,0,nRead); :(gZ\q">k
} uM|*y-4
catch(Exception e){e.printStackTrace ();} Kppi N+||
} M{:}.H<a
} uEqL Dg
^p3"_;p)h
e%_2n=p~)%
//打印回应的头信息 \D Oqx
public void logResponseHead(HttpURLConnection con) I6!~(ND7
{ >p"ytRu^
for(int i=1;;i++) q^5j&jx Vl
{ RJ+i~;-
String header=con.getHeaderFieldKey(i); CHxu%-g
if(header!=null) yr=$a3web;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); K)!yOa'fH
Utility.log(header+" : "+con.getHeaderField(header)); ?J[m)Uo/K
else "_!D b&AH
break; GZ xG!r-
} 3^NHVg
} BC|=-^(
[Aqy%mbG
:Y/>] tS4
public void splitterStop() PX7@3Y
{ ECq(i(
bStop = true; `r?xo7
} tCZ3n
$H}G'LqiG
/Z':wu\
} ,+LX.f&/8!
,|:TML
M.b1=Y
/* X9ua&T2(l
**FileAccess.java v[-.]b*5A$
*//文件访问(定位，写) M1UabqQ
package NetFox; O{YT6&.S0
import java.io.*; `XT8}9z!
=8`!Ph@(
;/hR#>ib
public class FileAccessI implements Serializable{ Yz"B
dXwfOC\\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e+'PRVc
RandomAccessFile oSavedFile; Pn&!C*,
long nPos; W8bh49
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`;X~$uS
public FileAccessI() throws IOException S}mZU!
{ \L6kCY
this("",0); ,drbj.0-
} c)L1@qdZ
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G&2UXr3
public FileAccessI(String sName,long nPos) throws IOException Dm^Bk?#(
{ 2=?:(e9
oSavedFile = new RandomAccessFile(sName,"rw"); *?l-:bc]
this.nPos = nPos; l*l?aI
oSavedFile.seek(nPos); DL*/hbG
} yUUg8xbpxF
*O5Ysk^|
q:iB}ch5R
public synchronized int write(byte[] b,int nStart,int nLen) Npr<{}ZE
{ Ah_,5Z@&R
int n = -1; D]P_tJI
try{ LtJl\m.th
oSavedFile.write(b,nStart,nLen); bi:TX<K+
n = nLen; Q/u2Q;j>
} =qg;K'M5
catch(IOException e) )(4.7>
{ pbXh}YJ&
e.printStackTrace (); W`vgH/lSnZ
} CC,f*I
AlVBhR`
g`n5-D@3
return n; YA?46[:
} 2#y-3y<G
mFGiysM
d?9b6k?
} p?6`mH
o@5zf{-
$FJf8u`
/* Ra!Br6
**SiteInfoBean.java g)L?C'BG
*/ X5Fi , /H
package NetFox; w4<n=k
:(?F(Q^
VhfMj|
public class SiteInfoBean { F<YXkG4pO
LBw$K0
V_Xq&!HN[
private String sSiteURL; //Site's URL GN=ugP 9
private String sFilePath; //Saved File's Path lL$no7HBy
private String sFileName; //Saved File's Name 0W6jF5T
private int nSplitter; //Count of Splited Downloading File NB.s2I7
Zr#\>h'c
->u}b?aF
public SiteInfoBean() #GVf+8"
{//nSplitter的缺省值为5 R2Y.s^
//default value of nSplitter is 5 Z`jSpgWR
this("","","",5); d7U%Q8?wUR
} >u0B ~9_E
Ia%S=xU{=
9e _8Z@|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Qk)E:
{ aS3Fvk0R{h
sSiteURL= sURL; VZ1u/O?ub
sFilePath = sPath; fgW>~m.W
sFileName = sName; Yp@i{$IUW
this.nSplitter = nSpiltter; `iQ9 9
[+2iwfD
M/LC:,
} Zk*!,,P!
1(`UzC=R|
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public String getSSiteURL() M\!z='Fi
{ Xf/qUao
return sSiteURL; _Z0O]>KH
} #[ TOe
]7/6u.G7R
mNDd>4%H_
public void setSSiteURL(String value) CYHo~VIK
{ g54b}vzm
sSiteURL = value; y yqya[-11
} Kd|@
@ rG=>??k
@@pI>~#zh
public String getSFilePath() =hq+9 R8=
{ ~}@cSv'(1
return sFilePath; ^)i1b:4
} B4kJ 7Pdny
tvEf-z
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public void setSFilePath(String value) 6b7SA,
{ KwxO%/-}S
sFilePath = value; AD0pmD
} cd3;uB4\,
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L; (J6p]h
public String getSFileName() T*bBw
{ T~G~M/
return sFileName; tEl_a~s*3?
} /s|4aro
+)U>mm,
iRsK;)<
public void setSFileName(String value) '^ob3N/Y [
{ xL#UMvZ>;h
sFileName = value; +/|t8zFWs
} V'm4DR#M
W*jwf@ 0
s+7#TdhA
public int getNSplitter() UR'P,
{ Dqg~g|(Q<
return nSplitter; G\ m`{jv
} i8+[-mh
tO8<N'TD
/5&'U!:+
public void setNSplitter(int nCount) SMIr@*R
{ u0?,CQPL
nSplitter = nCount; t(Sjo8, b
} =1e>$E#
} Y-y<gW
oJln"-M1nx
dHJ#xmE!pP
/* *)0-N!N#)
**Utility.java J<27w3bs~p
*/ }N`m7PSf
package NetFox; [~UCYYl
3 6-Sw
M.h8Kr!.
public class Utility { w^N3Ma
kY.3x#w
T$vDw|KSVP
public Utility() M_Z(+k{Gy
{ %D $+Z(
@q<F_'7is
m|%ly
} l/:23\
T/Fj0'
//线程睡眠 rc()Eo50
public static void sleep(int nSecond) IuN:*P
{ 0.kQqy~5
try{ _YPu
Thread.sleep(nSecond); KoF_G[m
} HCOE'24I
catch(Exception e) Bq*aP*jv
{ ,o68xfdZVW
e.printStackTrace (); [_w;=l0 ;
} S*9qpes-m|
} qdY*y&}"J
Udl8?EVSz
//日志 %wk3&EC.
public static void log(String sMsg) MFqM6_
{ /KLs+^c5
System.err.println(sMsg); 9n!IdqKN
} C[IY9s:Pf
SQ0t28N3h
#dEMjD
public static void log(int sMsg) &* 1iW(x
{ GAY f.L"
System.err.println(sMsg); 8-uRn38
} Y>i5ubR~
} b@?pofZ`k
vzPuk|q3
z(JDLd
/* p0Ra`*f
**TestMethod.java 86HK4sES
*/ `S+B-I0
package NetFox; @teNT"
Kh,zp{
JVawWw0q
public class TestMethod { :0'2m@x~
)"4v0dv
*p=a-s5-
public TestMethod() 2Pz)vnV"
{ ///xx/weblogic60b2_win.exe NU{`eM
try{ N"Mw1R4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jGaI6G'N
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); lk`,s
SiteFileFetch fileFetch = new SiteFileFetch(bean); ),;O3:n
fileFetch.start(); zd-qQ.j0
} (yxHXO9N
catch(Exception e){e.printStackTrace ();} %SJ2W>e
@b5zHXF83E
.M zAkZ=
} Wv4o:_}
]UFbG40Zo
WO<a^g {
public static void main(String[] args) SdM@7%UK
{ 71(C@/J
new TestMethod(); ?@LqrKj11
} \2huDNW& !
} uqFYa bU
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