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)); F~x>\?iN
} Iz9b5
for(int i=0;i<nEndPos.length-1;i++) z<,-:=BC"
{ Qw.j
nEndPos = nStartPos[i+1]; f~{4hVA
} !1xX)XD4y
nEndPos[nEndPos.length-1] = nFileLength; (}MN16!
} T*rx5*:o
} %Mr^~7nN
{qb2!}FQ
Kq;s${ |G
//启动子线程 []hC*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &'oZ]}^0
for(int i=0;i<nStartPos.length;i++) f~w!Z
{ DGO\&^GT^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fl o9iifZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -HUlB|Q8r
nStartPos,nEndPos,i); zA*I=3E(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3oMhsQz~z
fileSplitterFetch.start(); /s "Lsbe
} S(Q=2Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5'S~PQka*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d< b,].
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", */y (~O6
nEndPos = " + nFileLength); 4x2,X`pe3
// fileSplitterFetch[nPos.length-1].start(); P:fcbfH+
Q$8K-5U%
i]}`e>fF
//等待子线程结束 Hg2Rcl
//int count = 0; i2 G.<(3O
//是否结束while循环 aW(Hn[}^
boolean breakWhile = false; FwqaWEk
<L+y 6B
evGUl~</~
while(!bStop) >6A8+=
{ LyG&FOf?
write_nPos(); PiF&0;
Utility.sleep(500); agj_l}=gO
breakWhile = true; UzT"Rb:e
DgODTxiX
N~+e\K6
for(int i=0;i<nStartPos.length;i++) C(}N*e1
{ 'yNS(Bg=
if(!fileSplitterFetch.bDownOver) Zx 5Ue#I
{ -;j '=?
breakWhile = false; y8$I=
break; ?V' zG&n@
} cA{7*=G?
} :4/37R(~l8
if(breakWhile) oP_}C[
break; MP$9W)
?C(3TKH
uc]`^,`2/
//count++; `]j:''K
//if(count>4) bz|-x"qk
// siteStop(); aM|;3j1p
} +\U#:gmw
DLd1Cl:"~:
n 'E:uXv"
System.err.println("文件下载结束！"); JXq l=/%
} >$G'=N:=X&
catch(Exception e){e.printStackTrace ();} _ls i,kg?
} f]48>LRE8
Eh&-b6:
T':} p2}w+
//获得文件长度 PIM4c
public long getFileSize() jP}Ix8vc=
{ #}S<O_
int nFileLength = -1; PDkg@#&y,k
try{ >*Ctp +X@
URL url = new URL(siteInfoBean.getSSiteURL()); {8T/;K@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L&hv:+3N
httpConnection.setRequestProperty("User-Agent","NetFox"); _m*FHi
A8T8+M:
U5yBU9\G
int responseCode=httpConnection.getResponseCode(); T,/:5L9
if(responseCode>=400) T7?cnK"
{ S,vh
processErrorCode(responseCode); a~&euT2
return -2; //-2 represent access is error ZK5 wZU
} 5F$~ZDu
<5o oML]nP
F}c}I8Ao
String sHeader; /&+*X)#v
k nljc^
og`K!d~
for(int i=1;;i++) C9^C4
{ _*fOn@Vwo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^T*'B-`C7X
//Utility.log(in.readLine()); 9wdl1QS
sHeader=httpConnection.getHeaderFieldKey(i); A.cNOous|
if(sHeader!=null) Td5yRN! ?
{ $[V-M\q
if(sHeader.equals("Content-Length")) PnZY%+[I
{ *9tRhRc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _&e$?hY
break; (O"-6`w[
} ^NXxMC(e+
} 6h?)x
else +;bP.[Z
break; \S0QZQbz/
} {<Y\flj{@m
} ).IK[5Q`
catch(IOException e){e.printStackTrace ();} odKdpa Zc[
catch(Exception e){e.printStackTrace ();} $7*@TMX
R?HuDxHk
eXi}-~o
Utility.log(nFileLength); -lS(W^r4
w5;d/r<q
SAhk`_
return nFileLength; *K;s*-|U
} Igh=Z %
@1s 2#)l(
3|PV.
//保存下载信息（文件指针位置） s'/ZtH6>C
private void write_nPos() cYz|Ux
{ cs?IzIQ
try{ ET;-'vd
output = new DataOutputStream(new FileOutputStream(tmpFile)); ''H;/&nDX
output.writeInt(nStartPos.length); ',]^Qu`a
for(int i=0;i<nStartPos.length;i++) p4vX3?&1W
{ /"@cv{
// output.writeLong(nPos); =F09@C,
output.writeLong(fileSplitterFetch.nStartPos); }#2I/dn
output.writeLong(fileSplitterFetch.nEndPos); J+m1d\lBu
} b}!T!IP}
output.close(); YI?tmqzt
} \.YJs"<3
catch(IOException e){e.printStackTrace ();} "'~&D/7
catch(Exception e){e.printStackTrace ();} 5DL(#9F8b9
} ),XDY_9K
rmeGk&*R8
ht2J, 1t
//读取保存的下载信息（文件指针位置） }aL&3[>>
private void read_nPos() (BGflb
{ upiYo(sN.
try{ 3;F up4!4}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C(n_*8{
int nCount = input.readInt(); cUr5x8<W).
nStartPos = new long[nCount]; _ ($U\FW
nEndPos = new long[nCount]; <xUX&J=;
for(int i=0;i<nStartPos.length;i++) NIG* }[}P
{ L[tq@[(IJ
nStartPos = input.readLong(); 2%vG7o,#
nEndPos = input.readLong(); APyH.]mQ
} vngn^2
input.close(); Y%^qt]u.8
} qVE<voB8
catch(IOException e){e.printStackTrace ();} R|[gEavFl
catch(Exception e){e.printStackTrace ();} cH6J:0>W
} d "25e"(~F
S5[}kfe
:"gu=u!
private void processErrorCode(int nErrorCode) K_%gda|l+
{ :kvQ3E0
System.err.println("Error Code : " + nErrorCode); (w`j?c1
} pYh\l.@qf
yM*_"z!L
Rbcu5.6
//停止文件下载 Jk57| )/
public void siteStop() T@d4NF#
{ bzh:
bStop = true; )!Zm*(
for(int i=0;i<nStartPos.length;i++) lsU`~3nr
fileSplitterFetch.splitterStop(); { a_&L
2E0oLl[
D~)bAPAD
} 3x)jab
} D!mx&O9
//负责部分文件的抓取 yT[)V[}
**FileSplitterFetch.java ,6aF~p;wI|
*/ [y"Yi PK
package NetFox; 0E#?H0<OeG
cUTG! P\R
T:g%b @
import java.io.*; lT_dzO
import java.net.*; n( zzH
]{18-=
8|tnhA]~
public class FileSplitterFetch extends Thread { Esf\Bo"
T=':$(t
(#nB90E{*
String sURL; //File URL `!<#'PR
long nStartPos; //File Snippet Start Position nZ[`Yrq)0
long nEndPos; //File Snippet End Position VYkUUp
int nThreadID; //Thread's ID @_ Tq>tOr&
boolean bDownOver = false; //Downing is over =l>=]O~h
boolean bStop = false; //Stop identical ohi0_mBz
FileAccessI fileAccessI = null; //File Access interface #!t6'*
{/i&o
Y?:"nhN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <MJ-w1A
{ mpD[k9`x#
this.sURL = sURL; .@psW0T%
this.nStartPos = nStart; lS?#(}a1)
this.nEndPos = nEnd; `:W}yo<F
nThreadID = id; 8Fv4\dr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0a:@DOzT
} Wm/0Pi
j+Q+.39s-~
XQZiJ %'
public void run() &3:<WU:U
{ =oTj3+7
while(nStartPos < nEndPos && !bStop) ]3uj~la
{ C)ic;!$Qhb
!*o{xq
{}P~nP
try{ Jt3*(+J>/
URL url = new URL(sURL); 8d(l)[GZt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &.JJhX
httpConnection.setRequestProperty("User-Agent","NetFox"); vJe c+a
String sProperty = "bytes="+nStartPos+"-"; XV1XzG#C
httpConnection.setRequestProperty("RANGE",sProperty); `Dp4Z>| K
Utility.log(sProperty); f& Vx`oj
&U\//
"Rn@yZV
InputStream input = httpConnection.getInputStream(); UQjYWXvi
//logResponseHead(httpConnection); pW_mS|
*A0*.>@N
`E|>K\
byte[] b = new byte[1024]; b{;LbHq+G
int nRead; $Km~x
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zEDN^K '
{ w@H@[x
nStartPos += fileAccessI.write(b,0,nRead); K;]Dh?
//if(nThreadID == 1) 9&{HD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PNH>LT^
} 9r ](/"=f
'rrnTd c
# ELYPp]6
Utility.log("Thread " + nThreadID + " is over!"); %- Ga^[
bDownOver = true; ps33&
//nPos = fileAccessI.write (b,0,nRead); Aa^w{D
} 0@&/W-VXg
catch(Exception e){e.printStackTrace ();} zIr4!|X
} G6s3\de#U
} |Rz}bsrZ
#I#_gjJkx
+1c[!;'
//打印回应的头信息 %DKC/%
public void logResponseHead(HttpURLConnection con) 8F/zrPG
{ |][PbN D
for(int i=1;;i++) 3U*4E?g
{ 0O(Vyy
String header=con.getHeaderFieldKey(i); 2Hk21y\
if(header!=null) $F6GCM3Cx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G`f|#-}
Utility.log(header+" : "+con.getHeaderField(header)); gi+FL_8CzU
else !ZY1AhGZ
break; \W|ymV_Ki
} Eo@rrM:
} t-Ble
t-SZBNb
AvB21~t&]
public void splitterStop() .e\PCf9v
{ lDVgW}o@
bStop = true; ^G "Qp8 "
} 4@0Z<8Mo
cL4Xh|NBp
F<{k~
} 6iY(RYZ7-
5kCXy$"%
nLR
/* % @!hf!
**FileAccess.java ES)_X:\X?V
*//文件访问(定位，写) eWXR #g!%>
package NetFox; Wr+1e1[
import java.io.*; RtEx WTc
Q1!+wC
f]2;s#cu
public class FileAccessI implements Serializable{ xu@xP5GB^
WA5.qw
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #-l+cu{
RandomAccessFile oSavedFile; =[0|qGzg
long nPos; q-S#[I+g
tO3#kV\,
IV%Rph>d
public FileAccessI() throws IOException z}Vg4\x&
{ 0|,Ij$
this("",0); CDT;AdRw7
} r+tHVh
3!8u
$5DlCN
public FileAccessI(String sName,long nPos) throws IOException M2nUY`%#v
{ ITD&wg
oSavedFile = new RandomAccessFile(sName,"rw"); L#fK ,r8
this.nPos = nPos; mNJCV8 <
oSavedFile.seek(nPos); 6UU<:KH
} 0JW =RW
u.}H)wt
<(1[n pS&+
public synchronized int write(byte[] b,int nStart,int nLen) (Mw+SM3<
{ w,t !<i
int n = -1; gO/\Yi
try{ QE721y
oSavedFile.write(b,nStart,nLen); biRkqc;
n = nLen; ADA}_|O
} W9S6 SO^\
catch(IOException e) .u]d5z BR
{ v=DC3oh-
e.printStackTrace (); u R]8ZT")
} Dn`
z~ua#(z1S
V14+?L
return n; znAo]F9=J"
} 9}+X#ma.Nc
27MwZz
bnH:|-?q
} |<%v`*
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B/Ltb^a
/* s0DT1s&
**SiteInfoBean.java 'f8'|o)
*/ ;_0frX
package NetFox; $y%IM`/w
GE=PaYz
>[Tt'.S!?
public class SiteInfoBean { RL*b47,
wM}AWmH
Kd*=-
private String sSiteURL; //Site's URL nuw7pEW@?
private String sFilePath; //Saved File's Path t >Rh
private String sFileName; //Saved File's Name n*9nzx#q
private int nSplitter; //Count of Splited Downloading File 2I7|hZ,
o3:BH@@
D5Z)"~'
public SiteInfoBean() -op)X>
{//nSplitter的缺省值为5 fnIF<Zt
//default value of nSplitter is 5 )[ejb?{d
this("","","",5); 8[#EC3
} U[z2{\
f<y3/jl4
a3,A_M}M'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Hk$do`H-=Y
{ UK)wV
sSiteURL= sURL; 4~2 9,
sFilePath = sPath; t_+owiF)M
sFileName = sName; B_RF)meux
this.nSplitter = nSpiltter; &ViK9
-?-yeJP2
\y+^r|IL
} ZuKOscVS#T
"`h.8=-
COj^pdE3
public String getSSiteURL() ;WgzR_'!'
{ ,[3}t%Da
return sSiteURL; fP 3t0cp
} PJ,G_+b!
(-VH=,Md
f`8?]@y{
public void setSSiteURL(String value) B;nIKZ
{ *\*]:BIe&v
sSiteURL = value; gUYTVp Vf
} a%`L+b5-$
)~IOsTjI
\Qq YH^M
public String getSFilePath() X]dN1/_
{ EAE#AB-A
return sFilePath; yoz-BS
} )(pgJLW
L]l?_#*x
s.a@uR^
public void setSFilePath(String value) s+^1\
{ 4\j1+&W
sFilePath = value; 1B$8<NCQ=?
} 'C@yJf
%BQ?DTtb7'
W,:j>vg
public String getSFileName() 09i77
{ Vddod
return sFileName; 8C*xrg#g:
} sXYXBX[
5C9 .h:c4y
rS+ >oP}
public void setSFileName(String value) z?GtC{L9
{ 'a$/!~X
sFileName = value; |)mUO:*
} M0hR]4T
g!i45]6[Nw
#%{
public int getNSplitter() %}unlSTPP
{ }H/94]~tH
return nSplitter; ~+PKWs'}F
} lB7/oa1]>
iz+,,UH
}4Q3S1|U
public void setNSplitter(int nCount) v!=e]w6{
{ Z1p%6f`
nSplitter = nCount; w9Nk8OsL
} &SPIu,
} Ga` 8oY+~
bPMf='F{r
SQN{/")T
/* <~e*YrJ?-
**Utility.java SCjVzvG$yg
*/ 2o7o~r
package NetFox; BF"eVKA
%Rf{v5
u3DFgl3-7
public class Utility { sosIu
kmt+E'^]
4$4Tx9C
public Utility() S+?*l4QK
{ .5tXwxad"
W k"_lJ
|aj]]l[@S
} H~:g=Zw
}ee3'LUPX
//线程睡眠 j`_Z`eG
public static void sleep(int nSecond) e.(RhajB
{ ~8'HX*B]z
try{ |1Nz8Vr.
Thread.sleep(nSecond); mn(MgJKQ\
} ANR611-a
catch(Exception e) )P|/<>z
{ V1A7hRjxvG
e.printStackTrace (); yKmHTjX=
} #XNURj
} "*KOU2}C
knWI7
//日志 i6i;{\tc
public static void log(String sMsg) F |_mCwA
{ ,pW^>J
System.err.println(sMsg); VotI5O $
} N8!e(YK_
r)<n)eXeD
.SBN^fq
public static void log(int sMsg) dhuIVBp!!e
{ T<RWz
System.err.println(sMsg); Iapzhy2l
} >_X(rar0
} wHQYBYKcd
z] |Y
qLB(Th\&'
/* /#}%c'
**TestMethod.java 7/\SN04l
*/ / $'M
package NetFox; MF$NcU
P[e#j
l%`~aVGJ
public class TestMethod { -Q1~lN m:
b+BX >$
0%3T'N%
public TestMethod() C+gu'hD
{ ///xx/weblogic60b2_win.exe 1i Q(q\%
try{ 5zt5]zl'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l_2YPon
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q}#H|@
SiteFileFetch fileFetch = new SiteFileFetch(bean); +:z%#D
fileFetch.start(); y|WOw(#
} CS"p3$7,
catch(Exception e){e.printStackTrace ();} P?y{9H*
S_Vquw(+
eh3CVgH91;
} -AKbXkc~\
o7g6*hJz
?\a';@h
public static void main(String[] args) ,Nev7X[0
{ {1GIiP-U
new TestMethod(); "~IGE3{
} nm<S#i*
} u?8e>a
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