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)); sCu+Lg~f
} aj}(E+
for(int i=0;i<nEndPos.length-1;i++) Vrvic4
{ 5[Pr|AY
nEndPos = nStartPos[i+1]; l{D'uI[&
} M2U&?V C!
nEndPos[nEndPos.length-1] = nFileLength; rLX4jT^
} YTw#JOO
} j+HHQd7Y
L;od6<.*m
@&}q}D
//启动子线程 Vi$-Bw$@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pBw0"ff
for(int i=0;i<nStartPos.length;i++) 07hF2[i
{ ~ Uo)0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]TaN{"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K!KMQr`
nStartPos,nEndPos,i); n!qV>k9Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H}:LQ~_2
fileSplitterFetch.start(); 4WB-Ec
} AdWq Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $k$4% 7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6eokCc"o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5K?}}Frrt`
nEndPos = " + nFileLength); C2{lf^9:&
// fileSplitterFetch[nPos.length-1].start(); D0N9Ksq
\);4F=h}f
Y{*u&^0{
//等待子线程结束 r `eU~7
//int count = 0; l (3bW1{n
//是否结束while循环 P<K){V
boolean breakWhile = false; B*gdgM*`
O=9-Qv|
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while(!bStop) CpQN,-4
{ $u/E\l
write_nPos(); +NFzSal
Utility.sleep(500); ci+tdMA
breakWhile = true; <ioO,oS'
S'HnBn /
ko^\HSXl
for(int i=0;i<nStartPos.length;i++) 46k?b|Q
{ XerbUkZ
if(!fileSplitterFetch.bDownOver) 95<EN(oUD
{ f}D1|\7
breakWhile = false; F"N60>>
break; N&[D>G]>v
} |_G )qp;
} nW|wY.
if(breakWhile) boo }u
break; &* E+N[
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7+hK~
//count++; c=AOkX3UD
//if(count>4) e]Zngt?b
// siteStop(); al20V
} A?G^\I~v
!yhh8p3
&ZTr
System.err.println("文件下载结束！"); 3R&lqxhg
} _`#3f1F@[
catch(Exception e){e.printStackTrace ();} &5L<i3BX
} cv/_r#vN
^V%rag
Wpc|`e<
//获得文件长度 rS1fK1dys
public long getFileSize() *Y@nVi
{ RyRpl*^
int nFileLength = -1; Pm$q]A~
try{ t^ZV|s 1
URL url = new URL(siteInfoBean.getSSiteURL()); }y%oT P&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [{r}u
httpConnection.setRequestProperty("User-Agent","NetFox"); &gI~LP
Ssk}e=]
u=YX9Mo!
int responseCode=httpConnection.getResponseCode(); Qeu\&%C!<
if(responseCode>=400) ?h!i0Rsm
{ }za[E>z
processErrorCode(responseCode); '<0J@^vZ
return -2; //-2 represent access is error I=;+n-
} lHZU iB
^GBe)~MT
,j5&6X=1M
String sHeader; l$hJE;n
S1U@UC
N4*G{g
for(int i=1;;i++) a" H WGY
{ ~8m=1)A{(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <94_@3
//Utility.log(in.readLine()); (5Sivw*mP
sHeader=httpConnection.getHeaderFieldKey(i); IG3,XW
if(sHeader!=null) 6DZ),F,M
{ Iyo@r%I
if(sHeader.equals("Content-Length")) kPjd_8z2n
{ ``A 0WN
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r_YIpnJ
break; 7#<c>~
} 8?Z4-6!{V,
} +w8R!jdA
else y ?G_y
break; E\u#t$
} ?b!Fa
} <|?K%FP7Z
catch(IOException e){e.printStackTrace ();} Y4IGDY*
catch(Exception e){e.printStackTrace ();} 5 |/9}^T
Ez{MU@Fk
ql<rU@
Utility.log(nFileLength); L>Mpi$L
C%~a`e|/Y
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return nFileLength; VxFOYC>p
} $F.kK%-*
A^2L~g[^Q
L^^4=ao0
//保存下载信息（文件指针位置） B4XZko(
private void write_nPos() gKg-O
{ CB~Q%QLG
try{ *MI*Rz?4
output = new DataOutputStream(new FileOutputStream(tmpFile)); S^Au#1e
output.writeInt(nStartPos.length); H[b}kZW:a
for(int i=0;i<nStartPos.length;i++) }qjCTEs}
{ v_<2H'*Q
// output.writeLong(nPos); iE.-FZc
output.writeLong(fileSplitterFetch.nStartPos); )wVIb)`R>Y
output.writeLong(fileSplitterFetch.nEndPos); :SV>+EDY
} $0^P0RAH
output.close(); {7MjP+\
} ^2]LV6I
catch(IOException e){e.printStackTrace ();} ^h&I H|
catch(Exception e){e.printStackTrace ();} 8^B;1`#
} ~ 7)A"t
an2AX%u
*4|Hqa
//读取保存的下载信息（文件指针位置） !6}O.Nu
private void read_nPos() L_em')
{ :D7|%KK
try{ oRp:B&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); TEsnNi 1
int nCount = input.readInt(); ~L7:2weV[
nStartPos = new long[nCount]; &:=$wc
nEndPos = new long[nCount]; ,YhwpkL
for(int i=0;i<nStartPos.length;i++) ,%YBG1E[y
{ }`yiT<z
nStartPos = input.readLong(); f f7(
nEndPos = input.readLong(); c<#<k}y
} \M]-bw`
input.close(); ^Y{D^\},
} ~Ki`Ze"x
catch(IOException e){e.printStackTrace ();} H6aM&r9}
catch(Exception e){e.printStackTrace ();} Q:6VYONN
} ESb ]}c:
tZ2e!<C
[0[M'![8M
private void processErrorCode(int nErrorCode) YDmWN#
{ @ \2#Dpr
System.err.println("Error Code : " + nErrorCode); #=}$OFg
} &W }<:WH~
^6p'YYj"5
~2u\
//停止文件下载 buk=p-oi
public void siteStop() l2hG$idC
{ `:M^8SYrL
bStop = true; "8V{5e!%j'
for(int i=0;i<nStartPos.length;i++) V,%L~dI
fileSplitterFetch.splitterStop(); SK$Vk[c]
}jSj+*
x?D/.vrOY
} bl/,*Wx:4.
} T@^]i&
//负责部分文件的抓取 l0tYG[
**FileSplitterFetch.java z(c9,3
*/ b]gY~cbI8
package NetFox; 8Z85D
=neL}Fav56
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import java.io.*; xn}BB}s{t
import java.net.*; *@ED}Mj+
GbU@BN+_
!NKmx=I]
public class FileSplitterFetch extends Thread { oN(-rWdhZ
5,b]V)4
;K:8#XuV
String sURL; //File URL !PUp>(
long nStartPos; //File Snippet Start Position [;O^[Iybf:
long nEndPos; //File Snippet End Position A[UP"P~u/
int nThreadID; //Thread's ID u@%|kc`
boolean bDownOver = false; //Downing is over jJwkuh8R
boolean bStop = false; //Stop identical Ul Mi.;/^
FileAccessI fileAccessI = null; //File Access interface /48 =UK
+?`b=6e(`
:u%$0p>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >CgO<\
{ \|Dei);k
this.sURL = sURL; 2H?d+6Pt3
this.nStartPos = nStart; %c^ m\E
this.nEndPos = nEnd; wX1ig
nThreadID = id; fMK#x\.4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l54|Q
} FquFRx
Sav`%0q?7a
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public void run() .gZZCf&?
{ oUW<4l
while(nStartPos < nEndPos && !bStop) u}H$-$jE
{ e9u@`ZC07
dYOF2si~%
3/M.0}e
try{ F@YV]u>N
URL url = new URL(sURL); |;;!8VO3J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s ?l%L!
httpConnection.setRequestProperty("User-Agent","NetFox"); zREJ#r
String sProperty = "bytes="+nStartPos+"-"; B!aK
httpConnection.setRequestProperty("RANGE",sProperty); YRB%:D@u
Utility.log(sProperty); Fm j=
]@xL=%
|Svk^mq
InputStream input = httpConnection.getInputStream(); S-E++f9D~
//logResponseHead(httpConnection); 6 o[/F3`
2f:Mm'XdB
0|)19LR
byte[] b = new byte[1024]; oJaAM|7uv
int nRead; |LYKc.xo
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |9NIGg'n
{ 9Yw]Y5l
nStartPos += fileAccessI.write(b,0,nRead); WO%h"'iJ
//if(nThreadID == 1) r25Z`X Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fU*C/ d3
} ,9/5T:2
Ex($
9F_6}.O
Utility.log("Thread " + nThreadID + " is over!"); +?N}Y{Y&
bDownOver = true; fCEz-TMW
//nPos = fileAccessI.write (b,0,nRead); kC^.4n om
} StQ@g
catch(Exception e){e.printStackTrace ();} rH}fLu8,;Q
} C%H9[%k
} kN'Thq/ZE
v}il(w;O
a[O6YgO
//打印回应的头信息 cNP/<8dq
public void logResponseHead(HttpURLConnection con) 0P 5BArJ?
{ N <pbO#e
for(int i=1;;i++) :Z2tig nL
{ F ! )-|n}
String header=con.getHeaderFieldKey(i); |6B6?'
if(header!=null) }bfn_ G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *)PG-$6X&
Utility.log(header+" : "+con.getHeaderField(header)); `facFt[\
else {fG|_+tl3o
break; -Z?Ck!00
} F RH&B5w
} lYQtv=q
R#6H'TVE
Y-&|VE2
public void splitterStop() 2lz {_9
{ NV!4(_~
bStop = true; Hhf72IX
} Wu{&;$
=WRO\lgv.
3hJH(ToO
} U1^l+G^,~
k&DGJ5m$.
0(TvQ{
/* y\_wWE
**FileAccess.java 0!IPcZjY7
*//文件访问(定位，写) +2O=s<fp
package NetFox; MuSaK %
import java.io.*; Es:6
z_(eQP])
V [4n'LcE
public class FileAccessI implements Serializable{ @W [{2d
i_YW;x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }vsO^4Sjc
RandomAccessFile oSavedFile; )H+h;U
long nPos; s-5wbi.C
RO(iHR3cA
:1BM=_WwI
public FileAccessI() throws IOException Zi3T~:0p:
{ Sf5]=F-w
this("",0); Hd*Fc=>"Y
} 5byeWH0n3
|B|@GF?:
pU DO7Q]
public FileAccessI(String sName,long nPos) throws IOException r9;`
{ |J?:91
oSavedFile = new RandomAccessFile(sName,"rw"); C*j9Iaj
this.nPos = nPos; FAd``9kRT
oSavedFile.seek(nPos); x)\V lR
} '{^8_k\}B
5\?3$<1I
g$gS7!u,
public synchronized int write(byte[] b,int nStart,int nLen) q4k`)?k9
{ k1wr/G'H[
int n = -1; 9i[4"&K
try{ fn?VNZ`J
oSavedFile.write(b,nStart,nLen); Okoo(dfM
n = nLen; |<2 *v-a
} $/.<z(F
catch(IOException e) zg7G^!PU
{ NY 4C@@"
e.printStackTrace (); zze z~bv7:
} 8vO;IK]9b^
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return n; E4i@|jE~)
} rV U:VL`2
9C?cm:
FRS28D
} DOT=U _
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/* W1<.OO\J
**SiteInfoBean.java ?to1rFrU
*/ W7W3DBKtSm
package NetFox; 5R"2Wd
+0U#.|?
z[Z2H5[
public class SiteInfoBean { hafECs
4D GY6PS
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private String sSiteURL; //Site's URL Kc-4W6?$
private String sFilePath; //Saved File's Path v#Sj|47
private String sFileName; //Saved File's Name 'Y ,1OK
private int nSplitter; //Count of Splited Downloading File fIH#
5<^'Cy
\{:%v#ZZ
public SiteInfoBean() 1ThwvF%Qo
{//nSplitter的缺省值为5 >kZ6f4
//default value of nSplitter is 5 g?gqkoI
this("","","",5); +q l
} Z/n3aYM
[Ek42%
)ib7K1GJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :TlAL# s&
{ w)^\_uAlS
sSiteURL= sURL; OZa88&
sFilePath = sPath; ]ZDTn
sFileName = sName; #>"}q3RO
this.nSplitter = nSpiltter; 2Gm-\o&Td"
fqN75['n
@+$cZ3,
} U @)k3^
z'T=]- D
keaj3#O
public String getSSiteURL() NWb} OXK/
{ p %L1uwLG
return sSiteURL; .hc|t-7f
} ?Q;kZmQl
_/ct=
pFEZDf}:
public void setSSiteURL(String value) ' *}^@[&
{ rAM*\=
sSiteURL = value; ) b/n)%6
} ENO? ;
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epn#qeX
public String getSFilePath() !O 4<I_EY{
{ >dyhox2*"
return sFilePath; is9}ePC7Xu
} 5GaoJ v
oPCrD.s
FOeVRq:#
public void setSFilePath(String value) "Wo.8
{ n>br,bQe
sFilePath = value; xC[~Fyhp
} 0r0c|*[+4z
\QliHm!
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public String getSFileName() Q,D0kS P
{ <{E;s)hD?
return sFileName; J6eJIKK
} w2 /* `YO
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public void setSFileName(String value) u1tq2"D8
{ P@2tR5<R
sFileName = value; ,.[.SU#V
} P`p6J8}4
vc )9Re$
{,i=>%X*
public int getNSplitter() `b#/[3
{ `'*F1F
return nSplitter; 2H[=lY
} D!X>O}
*e%Dg{_
M8\G>0Hc6
public void setNSplitter(int nCount) I<c@uXXV;!
{ kmmL>fCV"M
nSplitter = nCount; "|F.'qZrm
} 3b+7^0frY#
} PP!l
,wEM Jh
Tku/OG'
/* /.7$`d
**Utility.java ,c@r` x
*/ cT_uJbP+
package NetFox; TP~( r
Hr /W6C
1a5?)D
public class Utility { U&,r4>V@h>
6 M*b6
r49UJE
public Utility() ?68$3;
{ wDB)&b
|~z8<
+xn&K"]:3
} chKF6n
Uy(vELB
//线程睡眠 W"W@WG9X0
public static void sleep(int nSecond) g4zT(,ZY
{ {`+bW"9
try{ A,3@j@bdy
Thread.sleep(nSecond); =t@:F
} h~,x7]w6
catch(Exception e) Bh\ [CY
{ g!p+rq_f
e.printStackTrace (); sVE>=0TVP
} Z~duJsH
} #x, ]D
2ZU@>W
//日志 ''$`;?t>
public static void log(String sMsg) Lv
{ 'Y hA
System.err.println(sMsg); $/4Wod*l
} h |s*i
R'vdk<
3js)niT9u
public static void log(int sMsg) E^oEG4X@
{ 3Qqnw{*
System.err.println(sMsg); %2^['8t#NH
} Bx\#`Y
} }W- K
d8xk&za
\7|s$ XQ\
/* 7'-)/Pk
**TestMethod.java Iu)L3_+
*/ 9c"0~7v
package NetFox; c80 }1
zzulVj*
EZ:I$X
public class TestMethod { L@C >-F|p
mJwv&E
A>qd2
public TestMethod() 1gF*Mf_7
{ ///xx/weblogic60b2_win.exe ph Wc8[Q
try{ :GN)7|:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~|X99?P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {Uik|
SiteFileFetch fileFetch = new SiteFileFetch(bean); Gh>"s#+
fileFetch.start(); ;yRwoTc)Y
} .a 'ETNY:>
catch(Exception e){e.printStackTrace ();} _DNkdS [[
|usnY
XS}Zq4H
} <ol$-1l#9
/.pa ??u
b|X>3(
public static void main(String[] args) y}(_SU
{ MuCQxzvkhf
new TestMethod(); `77;MGg*
} h#(.(d
} :d!i[W*
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