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)); /60[T@Mz
} $PTedJ}*Y
for(int i=0;i<nEndPos.length-1;i++) 7H[+iS0
{ g Sa,A
nEndPos = nStartPos[i+1]; O]PfQ
} tlcA\+%)
nEndPos[nEndPos.length-1] = nFileLength; }6S4yepl
} +2?0]6EQ
} jOuv\$
4u(}eE f7
96PVn
//启动子线程 1L9^N
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4p-$5Fk8}
for(int i=0;i<nStartPos.length;i++) W*s`1O>
{ 4]+ ^K`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6F(yH4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7"[lWC!As5
nStartPos,nEndPos,i); m9q%l_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nQP0<_S
fileSplitterFetch.start(); .(hb8 rCM
} &x3"Rq_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <r\)hx0ov
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); siG?Sd_2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %fyb?6?Y
nEndPos = " + nFileLength); xH f9N?
// fileSplitterFetch[nPos.length-1].start(); sEj:%`l|
7<tqT @c
b\+|g9Tm
//等待子线程结束 cj8r-Vu/N
//int count = 0; lLJb3[ e.
//是否结束while循环 XWvs~Xw@
boolean breakWhile = false; 8bysg9H0
}3*h`(Bv7
.*f;v4!
while(!bStop) >3kR~:;
{ bFVdv&
write_nPos(); s<dD>SU
Utility.sleep(500); RSi0IfG5
breakWhile = true; yk5P/H)
y,r`8
,,Db:4qfjD
for(int i=0;i<nStartPos.length;i++) U'lD|R,g
{ ,yqzk.
if(!fileSplitterFetch.bDownOver) njX:[_&
{ g SwG=e\
breakWhile = false; QbNv+Eu5
break; jQr~@15J#
} $XI<s$P%(%
} >4VU
if(breakWhile) ljis3{kn""
break; bOFLI#p&
2lSM`cw
FEZ6X
//count++; KGWENX_U
//if(count>4) q%'ovX(dm
// siteStop(); 395o[YZx*
} $ i&$ZdX
5]Ra?rF
IL=v[)en4
System.err.println("文件下载结束！"); Gzfb|9,q
} R] [M_ r
catch(Exception e){e.printStackTrace ();} (g)@wNBW
} e-')SB
'H'+6
h@~X*yLKh
//获得文件长度 iR_Syk`G*A
public long getFileSize() ICTtubjV"
{ _l,Z38
int nFileLength = -1; P3yiJ|vP
try{ StDmJ]
URL url = new URL(siteInfoBean.getSSiteURL()); dbuOiZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &`Di cfD
httpConnection.setRequestProperty("User-Agent","NetFox"); ~76.S
C~;0A!@]Y
bsP;
int responseCode=httpConnection.getResponseCode(); '=~y'nPG7
if(responseCode>=400) 7gMtnwT
{ KVcZ@0[S
processErrorCode(responseCode); CU;nrd"
return -2; //-2 represent access is error z-gwNE{
} &0eB@8{N
ke#;1
4@V]zfu^Q
String sHeader; 5p|@)
}>w
Ntnmd
for(int i=1;;i++) 4QN;o%,
{ b:QFD|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %1@<),
//Utility.log(in.readLine()); lp}WBd+
sHeader=httpConnection.getHeaderFieldKey(i); ^'fKey`
if(sHeader!=null) oGVSy`ku
{ -h@0 1
if(sHeader.equals("Content-Length")) :|M/+XPu
{ <ut DZ#k
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L_|uB
break; 7L+X\oaB
} BXo|CITso
} w&"w"
else =.X?LWKY
break; h*KHEg"+
} a-E-hX2
} w~U`+2a3
catch(IOException e){e.printStackTrace ();} rc$!$~|I3Z
catch(Exception e){e.printStackTrace ();} 6}T%m?/}
W|#ev*'F
euhZ4+
Utility.log(nFileLength); cXY'>N
=[K)<5,@
]pV1T
return nFileLength; =b!J)]
} ww($0A`ek
qZJ*J+
Z&w^9;30P
//保存下载信息（文件指针位置） kNj3!u$
private void write_nPos() V"H7zx
{ NoO+xLHw8
try{ 1mJ_I|98
output = new DataOutputStream(new FileOutputStream(tmpFile)); uvDoo6'
output.writeInt(nStartPos.length); 1bJ]3\
for(int i=0;i<nStartPos.length;i++) ~snF20
{ PS(j)I3
// output.writeLong(nPos); -?nT mzRc
output.writeLong(fileSplitterFetch.nStartPos); ewrWSffe
output.writeLong(fileSplitterFetch.nEndPos); EO&ACG
} tt]V$V
output.close(); 0['"m^l0S
} U('<iw,Yy
catch(IOException e){e.printStackTrace ();} R5eB,FN
catch(Exception e){e.printStackTrace ();} -t6R!ZI
} p,iCM?[|
zf,%BI[Hr
3rdfg
//读取保存的下载信息（文件指针位置） UY-IHz;&O-
private void read_nPos() B`B%:#
{ %i-lx`U
try{ "q^#39i?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S[~O')
int nCount = input.readInt(); cN WcNMm
nStartPos = new long[nCount]; =/g$bZ
nEndPos = new long[nCount]; BO4 K#H7
for(int i=0;i<nStartPos.length;i++) 9J7J/]7f
{ 'K3s4x($
nStartPos = input.readLong(); J`q}Ry;
nEndPos = input.readLong(); Yv>BOK
} 2]} Uov
input.close(); +&7Kk9^
} ,=Nw(GI
catch(IOException e){e.printStackTrace ();} F[CT l3X
catch(Exception e){e.printStackTrace ();} k9)u3
} i6md fp|k
Yxd{&47
'dc+M9u)_q
private void processErrorCode(int nErrorCode) Q*:h/Lhb&
{ vV.~76AD5
System.err.println("Error Code : " + nErrorCode); >4/L-y+
} :@ E1Pun?
|jk-@ Z*
&QTeGn
//停止文件下载 43>9)t
public void siteStop() Pc(n@'m~
{ rMHQzQ0%
bStop = true; ?7uKP}1|
for(int i=0;i<nStartPos.length;i++) Aw4?y[{H
fileSplitterFetch.splitterStop(); Fi'M"^:r{
z]c,}Q
OwA~(
} (9}eF)+O
} @yt2_
//负责部分文件的抓取 RM&H!E<#
**FileSplitterFetch.java Y=a v8Y|`
*/ ;tp]^iB#
package NetFox; sLG>>d3R1
'B3Wza.
y~ _za(k
import java.io.*; q#99iiG1
import java.net.*; JOrELrMx
5@czK*5
)@]6=*%
public class FileSplitterFetch extends Thread { ])V2}gH
*:\:5*SY
"Ap$Jl B
String sURL; //File URL vm\wO._
long nStartPos; //File Snippet Start Position (Pv`L
long nEndPos; //File Snippet End Position xHJ8?bDp
int nThreadID; //Thread's ID Q1`<fD
boolean bDownOver = false; //Downing is over 6F*-qb3
boolean bStop = false; //Stop identical heL$2dZ5H
FileAccessI fileAccessI = null; //File Access interface Tr8AG>
2(m85/Hr\;
RCBf;$O
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :8^M5}
{ _8Nw D_"
this.sURL = sURL; 1Xy8|OFc[
this.nStartPos = nStart; M3Khc#5S(
this.nEndPos = nEnd; P+dA~2k
nThreadID = id; Y=vVxVI\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B;Xoa,
} ItI0x
+@emX$cFV
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public void run() q=6Cc9FN
{ yo\N[h7
while(nStartPos < nEndPos && !bStop) EBoGJ_l
{ b , juF2
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DX}B0B
try{ TGU:(J'^
URL url = new URL(sURL); R_Zv'y6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w9RF2J
httpConnection.setRequestProperty("User-Agent","NetFox"); .dx 4,|6
String sProperty = "bytes="+nStartPos+"-"; %G;0T;0L
httpConnection.setRequestProperty("RANGE",sProperty); _wf5%(~b
Utility.log(sProperty); j G-
I|,pE**T
Y5dD|]F|
InputStream input = httpConnection.getInputStream(); ]} 61vV
//logResponseHead(httpConnection); q$r&4s)To
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z Yw;q3"
byte[] b = new byte[1024]; U;xu/xDRi
int nRead; Y^52~[w~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q#P$'7"
{ v(DwU!
nStartPos += fileAccessI.write(b,0,nRead); I eG=J4:*
//if(nThreadID == 1) yND"bF9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %35L=d[
} '_:(oAi,C
B*\$ /bk,
!FTNmyM~F
Utility.log("Thread " + nThreadID + " is over!"); 9-0<*)"b>
bDownOver = true; :e*DTVv8
//nPos = fileAccessI.write (b,0,nRead); \K}-I
} 7vn%kW=$
catch(Exception e){e.printStackTrace ();} ~C&*.ZR
} 9O;cJ)tXY
} qG<7hr@x]
t\h$&[[l'z
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//打印回应的头信息 ^ eQFg>
public void logResponseHead(HttpURLConnection con) '77~{jy
{ |]`hXr
for(int i=1;;i++) \(I0wEQo$
{ @q K]JK
String header=con.getHeaderFieldKey(i); 5?WYsj"
if(header!=null) *G9sy_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xwRhs!`t1
Utility.log(header+" : "+con.getHeaderField(header)); 5W/{h q8}}
else -LtK8wl^
break; m9in1RI%
} pkJ/oT
} 57wFf-P
{;s;.
|EKu2We*
public void splitterStop() E<tK4?i"
{ 0RUi\X4HI
bStop = true; O] Y v
} E<>*(x/\e
A{# Nwd>
"(v%1tGk
} iPq &Y*
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OS-sk!
/* ^W~p..DF
**FileAccess.java &(EHq
*//文件访问(定位，写) j[I`\"
package NetFox; aSC9&Nf;
import java.io.*; )p<WDiX1!e
y<pnp?x4
As~(7?]r
public class FileAccessI implements Serializable{ $&{ti.l
=-NiO@5o
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :_5/u|{
RandomAccessFile oSavedFile; <3TA>Dz
long nPos; :_ROJ
%f j+70
{%C*{,#+8q
public FileAccessI() throws IOException G?AG:%H%
{ <A>)[u
this("",0); |Os6V<u"
} !d,8kG
Qck|#tc
u7fK1 ^O
public FileAccessI(String sName,long nPos) throws IOException Rx7X_A}
{ V8WFQdXc
oSavedFile = new RandomAccessFile(sName,"rw"); uI~s8{0T6
this.nPos = nPos; 7ER|'j
oSavedFile.seek(nPos); G,f-.
} UH? p]4Nz
4[yIOs
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public synchronized int write(byte[] b,int nStart,int nLen) &;E5[jO^D
{ >5hhd38
int n = -1; (@r `$5D.b
try{ eg/<[ A:
oSavedFile.write(b,nStart,nLen); MP^ d}FL
n = nLen; AH#4wPxF
} :XG;ru%i
catch(IOException e) ujFzJdp3k
{ s&a1y~rv
e.printStackTrace (); Aw5pd7qKL
} a(IY\q[Wh
*T`-|H*6@
7j$Pt8$
return n; #>[a{<;Kn
} q5x[~]?
5O<>mCF
:i~W }r
} eS+g|$cW
~g#r6pzN-
4dawg8K`9
/* #3$\Iu
**SiteInfoBean.java izgp*M,
*/ @{hd{>K*
package NetFox; Bc7V)YK
G7GZDi
2)X4y"l
public class SiteInfoBean { 7F^#o-@=J
fu[K".
5cJ!"
private String sSiteURL; //Site's URL WWKvh
private String sFilePath; //Saved File's Path ^n1%OzGK#
private String sFileName; //Saved File's Name 0AK,&nbF
private int nSplitter; //Count of Splited Downloading File q:\g^_!OGA
<TGn=>u
t_z,>,BqJ
public SiteInfoBean() }t9.N`xu
{//nSplitter的缺省值为5 ko;>#::
//default value of nSplitter is 5 =U8Ek;Drp
this("","","",5); );V2?G`/
} S! Rc|6y%
uhyj5u)
O7d$YB_'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7hP<f}xL
{ ({r*=wAP
sSiteURL= sURL; #LlUxHv #
sFilePath = sPath; 3_Cp%~Gi-_
sFileName = sName; !Ucjax~
this.nSplitter = nSpiltter; fhPkEvJ
Sr?#wev]rn
qfY5Ww$8
} o+w;PP)+=
N`@NiJ(O;
Vd^g9
public String getSSiteURL() E 99hlY~1:
{ $YxBE`)d-
return sSiteURL; (*}yjUYLZ
} S$)*&46g
>Y7a4~ufko
2H71~~ c
public void setSSiteURL(String value) KmG
{ T>TWU:
sSiteURL = value; ca i<,3H
} K 0gI):
z>sbr<doa
@NhvnfZ
public String getSFilePath() 6E(Qx~iL
{ Y8M]Lwj
return sFilePath; }En
} !+>v[(OzM
qm/Q65>E
:NJ_n6E
public void setSFilePath(String value) =_$Qtq+h
{ ,B?~-2cCz
sFilePath = value; OsBo+fwT
} <,o>Wx*1C
W} WI; cI
Lbe\@S
public String getSFileName() .2d9?p3Y
{ :w}{$v}#D;
return sFileName; T134ZXqqz
} V7#v6!7A@
4BnSqwa_
EA ]+vq
public void setSFileName(String value) KT]Pw\y5
{ ? WJ> p
sFileName = value; ^`un'5Vk
} S$KFf=0
>U F
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public int getNSplitter() 3bO(?l`3h
{ BA\/YW @
return nSplitter; u]}s)SmDk
} l/;X?g5+
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4iSa7YqhBT
public void setNSplitter(int nCount) n]8<DX99Q0
{ %X#zj"
nSplitter = nCount; ~l;[@jsw F
} f{SB1M
} )`^p%k
6'\6OsH
dJ"iEb|4
/* hW{j\@R
**Utility.java *s@Qtgu
*/ U qG .:@T
package NetFox; +`3!I
V_plq6z
P[s8JDqu
public class Utility { fw ,\DFHO
Aw&tP[N[
U,nEbKJgk
public Utility() KWLbD#
{ v<Bynd-
l5L.5$N
VfT*7_
} ~]ZpA-*@Ut
N !TW!
//线程睡眠 (O0Urm
public static void sleep(int nSecond) R|i/lEq
{ Da"j E
try{ <n3!{w3<
Thread.sleep(nSecond); C6rg<tCH
} NcY608C
catch(Exception e) B"%{i-v>**
{ AT5aDEb^^
e.printStackTrace (); c-.t>r&
} $-[CG7VgX%
} 1S@vGq}
JxyB(
//日志 q^6+!&"
public static void log(String sMsg) A*W)bZs.
{ 6e7{Iy
System.err.println(sMsg); DxJX+.9K9
} 'Ei;^Y 1e
fS^!ZPe1
zt^48~ry
public static void log(int sMsg) ~|<m,)!
{ .*elggM
System.err.println(sMsg); 2h?uNW(0Q
} 610D%F
} WxF:~{
aL\nT XakX
j <o3JV
/* p!s}=wI`
**TestMethod.java ! !PYP'e
*/ znJ'iVf
package NetFox; k}~O}~-
1bGopi/
GguFo+YeZ
public class TestMethod { 52o x`t|
"s\L~R.&
3"F`ZJ]=
public TestMethod() $+7`Dy!
{ ///xx/weblogic60b2_win.exe 86z]<p (
try{ $8a(veXd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *b];|n{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iOG[>u0h
SiteFileFetch fileFetch = new SiteFileFetch(bean); jM\*A#Jo5
fileFetch.start(); vVL@K,q
} a ^%"7Ri
catch(Exception e){e.printStackTrace ();} [e1S^pI
s|D>-
W\18{mbuy
} (ND4Q[*6
-j&Tc`j_
['ksP-=
public static void main(String[] args) KoS*0U<g6
{ >2By +/!X
new TestMethod(); cHa]xmy%r'
} t=xOQ8
} *28pRvY:b
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