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)); )D?\ru H
} 'S]7:/CI
for(int i=0;i<nEndPos.length-1;i++) R%B"Gtl)
{ %5.aC|^}
nEndPos = nStartPos[i+1]; oU[Ba8qh
} p w(eWP
nEndPos[nEndPos.length-1] = nFileLength; X=$WsfN.h
} S3EM6`q'
} t-7^deG'/n
KKpO<TO
e%.Xya#\
//启动子线程 F/GfEMSE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #'m&<g,
for(int i=0;i<nStartPos.length;i++) G&8)5d[
{ :KY920/,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VQA}!p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CZaUrr
nStartPos,nEndPos,i); ]gI>ay"\QA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pt[H5
fileSplitterFetch.start(); <5rs~
} =xzDpn>f
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z/09~Hc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DL0jA/f
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )9LlM2+y
nEndPos = " + nFileLength); c|?0iN
// fileSplitterFetch[nPos.length-1].start(); F|.,lb |L
GiI|6z!
IoUQ~JviA
//等待子线程结束 6b&<5,=d:
//int count = 0; wXdtY
//是否结束while循环 Hjl{M>z
boolean breakWhile = false; {@j0?s
N0APX4j
. !gkJ
while(!bStop) LS1r}cl
{ 5cLq6[uO
write_nPos(); /O@'XWW
Utility.sleep(500); !J<}=G5
breakWhile = true; {c5%.<O
m?LnO5Vs
Gd^K,3:. T
for(int i=0;i<nStartPos.length;i++) LvP{"K;
{ |KSd@
if(!fileSplitterFetch.bDownOver) Fh t$7V
{ 4-lG{I_S:
breakWhile = false; 8w,U[aJm
break; $r0~&$T&
} x\HHu]
} LObS 7U
if(breakWhile) Bqo8G->
break; rzmd`)g
(pY'v/a-
FtBYPSGz
//count++; "{a-I=s\C
//if(count>4) Vy*&po[
// siteStop(); Ph[P$: 9
} :0K[fBa
fa#xEWaFr
s-^B)0T!
System.err.println("文件下载结束！"); 0Vu&UD
} /JaCbT?*T
catch(Exception e){e.printStackTrace ();} BGAqg=nDV
} QEd>T"@g
'C=8.P?
k&Z3v.
//获得文件长度 }9Yd[`
public long getFileSize() QP+zGXd}(
{ 9G)Sjn`AQ
int nFileLength = -1; BLc&q)
try{ GL4-v[]6I
URL url = new URL(siteInfoBean.getSSiteURL()); a`SQcNBf*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S 6e<2G=O
httpConnection.setRequestProperty("User-Agent","NetFox"); o80?B~o
+RIG8w]
ziFg+i%s
int responseCode=httpConnection.getResponseCode(); B^4D`0G[4
if(responseCode>=400) Yt^<^l77D
{ ym*,X@Qg^
processErrorCode(responseCode); GE+%V7
return -2; //-2 represent access is error $@ /K/"
} b-sbRR
4=]CAO=O
Z0yy<9q]2
String sHeader; ?_Sf
["FC
53y,eLf
for(int i=1;;i++) \W^Mo>l
{ <sXmk{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w&6c`az8
//Utility.log(in.readLine()); EBF608nWfW
sHeader=httpConnection.getHeaderFieldKey(i); $i# 1<Qj
if(sHeader!=null) | CNsa
{ k+*DPo@)
if(sHeader.equals("Content-Length")) V*an0@
{ SSi-Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~(%TQY5
break; 'G3;!xk$
} :\ %.x3T'
} 6U{&`8C
else f? sW^d;
break; 4[@`j{
} j8lWra\y
} -b1VY4m-
catch(IOException e){e.printStackTrace ();} 6.]x@=Wm
catch(Exception e){e.printStackTrace ();} kbij Zj{
`1I@tz|
&[]0yNG
Utility.log(nFileLength); Q/e$Ttt4J
OKDBzl
Vq7L:,N9
return nFileLength; 9C-!I,
} -8-BVU
Vwj^h
Qg dHIMY
//保存下载信息（文件指针位置） YHoj^=/b
private void write_nPos() EH;w <LvT
{ \Qp #utC0s
try{ x)'4u6;d
output = new DataOutputStream(new FileOutputStream(tmpFile)); YuO-a$BP
output.writeInt(nStartPos.length); JXR_klx
for(int i=0;i<nStartPos.length;i++) g.CUo:c
{ A]VcQ_e
// output.writeLong(nPos); C)2Waj}
output.writeLong(fileSplitterFetch.nStartPos); xRZ9.Agv_
output.writeLong(fileSplitterFetch.nEndPos); :5/P{Co(
} k!/"J ;
output.close(); Z,'#=K
} 8"2 Y$*)(
catch(IOException e){e.printStackTrace ();} 6#NptXB
catch(Exception e){e.printStackTrace ();} b>R/=tx
} !L3M\Q0
zu6Y*{$>g
T~I5W=y
//读取保存的下载信息（文件指针位置） zB6u%uWR
private void read_nPos() '\[o>n2
{ kNX"Vo]1
try{ ^X$k<nA;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); igNZe."V
int nCount = input.readInt(); 2i+'?.P
nStartPos = new long[nCount]; #q2cVN1
nEndPos = new long[nCount]; YyR)2j1O
for(int i=0;i<nStartPos.length;i++) Aj`zT'
{ 4z~ fn9g
nStartPos = input.readLong(); INQ0h`T
nEndPos = input.readLong(); >Le L%$
} _c}@Fi+E
input.close(); R-Y|;
} ;aA,H&
catch(IOException e){e.printStackTrace ();} ZVo%ssVt
catch(Exception e){e.printStackTrace ();} -i``yf?P
} "zSi9]j
x,W)qv
uus}NZ:*l
private void processErrorCode(int nErrorCode) L,Jl# S
{ /I2RU2|B
System.err.println("Error Code : " + nErrorCode); ~.4-\M6[
} TV$Pl[m
(<?6X9F:N
m>4jRr6sF
//停止文件下载 Y)@mL~){
public void siteStop() :Mz$~o<
{ S1Q2<<[
bStop = true; \79KU
for(int i=0;i<nStartPos.length;i++) R/)cEvB-0
fileSplitterFetch.splitterStop(); 'I|A*rO
b2OVg +3
q'kZ3G
} CJA5w[m
} cr!6qv1
//负责部分文件的抓取 =$`xis\
**FileSplitterFetch.java _akC^hT
*/ J 00<NRxj"
package NetFox; N>z<v\`
Do@:|n
SJY<#_b
import java.io.*; i~\fpay
import java.net.*; -uZ bVd
J[9yQ
$~UQKv>
public class FileSplitterFetch extends Thread { %x_c2
%GUu{n<6
0T,Qn{
String sURL; //File URL :>gzWVE<
long nStartPos; //File Snippet Start Position dI!x Ai
long nEndPos; //File Snippet End Position @=o1q=5@8
int nThreadID; //Thread's ID &IGTCTBP
boolean bDownOver = false; //Downing is over DXPiC[g]
boolean bStop = false; //Stop identical ,: X+NQ
FileAccessI fileAccessI = null; //File Access interface _RG!lmJV
eto3dJ!R
VO ^[7Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~YO-GX(
{ =|IB=
this.sURL = sURL; g+8j$w}
this.nStartPos = nStart; HA%%WSuf
this.nEndPos = nEnd; mx@F^
nThreadID = id; y=y=W5#;77
fileAccessI = new FileAccessI(sName,nStartPos);//定位 FoM4QO
} \tFg10
mQt';|X@
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public void run() h4CDZ
{ }>vf(9sF`
while(nStartPos < nEndPos && !bStop) wD>tR SW
{ ,<$6-3sC-
;2"#X2B
A:Z$i5%'
try{ t59"[kQ
URL url = new URL(sURL); @ mm*S:Gt#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8%s^>.rG
httpConnection.setRequestProperty("User-Agent","NetFox"); eCB(!Y|
String sProperty = "bytes="+nStartPos+"-"; B<c7&!B
httpConnection.setRequestProperty("RANGE",sProperty); 2 g"_*[
Utility.log(sProperty); 910Ym!\{:
-|^}~yOx0=
b#0y-bR
InputStream input = httpConnection.getInputStream(); j`I[M6Qxh
//logResponseHead(httpConnection); 7sECbbJT
5Cxh>,k
"Y@rNmBj
byte[] b = new byte[1024]; BcaMeb-Z
int nRead; kR%bdN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WrhC q6
{ xz#;F ,`ZR
nStartPos += fileAccessI.write(b,0,nRead); #*uSYGdc
//if(nThreadID == 1) LO@.aJpp
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %Kd&A*
} ,]@K6
.$b]rx7$~
e*_8B2da
Utility.log("Thread " + nThreadID + " is over!"); lcgT9m#
bDownOver = true; 96;17h$
//nPos = fileAccessI.write (b,0,nRead); xQ4D| &
} Tj@}O:q7:
catch(Exception e){e.printStackTrace ();} GF5WR e(E
} !=C4=xv
} dw,Nlf~*0
2SU G/-P#
Q\G8R^9j p
//打印回应的头信息 f!;i$Oif
public void logResponseHead(HttpURLConnection con) BQWEC,*N
{ !}wJ+R ^2
for(int i=1;;i++) "sF&WuW|
{ d;&'uiS
String header=con.getHeaderFieldKey(i); g~_cYy
if(header!=null) evf){XhT;n
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Kx9Cx5B
Utility.log(header+" : "+con.getHeaderField(header)); <mlQn?u
else ]bO{001y,
break; 9_'xq.uP
} b u%p,u!
} QC0^G,9.
T[M?:~
nt\6o?W
public void splitterStop() "~x\bSY
{ uEQH6~\{Nl
bStop = true; I@P[}XS
} kzr9-$eb
wVk2Fr(
]kLs2? \
} 0-"ps]X
G1M}g8 ]h
=O~1L m;
/* 2%0zPflT
**FileAccess.java `we2zT
*//文件访问(定位，写) "m +Eu|{
package NetFox; /b,+YyWi%
import java.io.*; N8(xz-6
8r/]Q
p,}-8#K[
public class FileAccessI implements Serializable{ yrO'15TB
FT73P0!8.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i_ws*7B<
RandomAccessFile oSavedFile; z<c^<hE:l
long nPos; %Rv&VFg
BDZB;DPb
eKn&`\j6
public FileAccessI() throws IOException %)*!(%\S*3
{ W"4E0!r
this("",0); +<6L>ZAL
} )hj77~{+
2D`@$)KL
{55{YDqx
public FileAccessI(String sName,long nPos) throws IOException )c5M;/s
{ 6XUcJ0
oSavedFile = new RandomAccessFile(sName,"rw"); $s.:wc^
this.nPos = nPos; _Hi;Y
oSavedFile.seek(nPos); o%h"gbvMY!
} N( E\
;RZ@t6^
W3*BdpTw
public synchronized int write(byte[] b,int nStart,int nLen) @B5@3zYs
{ [P8Y
int n = -1; +Y(cs&V*
try{ c#nFm&}dm
oSavedFile.write(b,nStart,nLen); kCxmC<34
n = nLen; 'p-jMD}O
} dgpo4'c}
catch(IOException e) s`xp6\$
{ E-_)w
e.printStackTrace (); '{XDhK
} :k8>)x] )
m8$6FN
7CYu"+Ea
return n; &0SGAJlec
} UTKS<.q
,e( |,u
S6,AY(V
} ;YNN)P%"
\c>9f"jS_
eS fT+UL
/* C$oY,A,
**SiteInfoBean.java l_iucN
*/ _1hc^j
package NetFox; 9>u2; 'Ls
&#v^y3r
A=!&2(
public class SiteInfoBean { xB3;%Lc
>8Zz<S&z
dsX{5
private String sSiteURL; //Site's URL +mhYr]Z
private String sFilePath; //Saved File's Path =$Sf]L
private String sFileName; //Saved File's Name (f5!36mz
private int nSplitter; //Count of Splited Downloading File J|_&3@r
^M6v;8EU
[ik D4p=
public SiteInfoBean() /XS6X
{//nSplitter的缺省值为5 '?t]iRCeI7
//default value of nSplitter is 5 LW?] ~|
this("","","",5); "5Oog<
} 4ao oBY$
]Rohf WHX
o,9E~Q'`{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u /JEQz1
{ ESiNW&u2
sSiteURL= sURL; |;'V":yDs
sFilePath = sPath; ~6.AE/ow
sFileName = sName; fF[n?:VV
this.nSplitter = nSpiltter; |TF,Aj
\D?6_ ,O
hD{+V!{
} B<DvH"+$
l@Ma{*s6=5
&WN4/=QW-J
public String getSSiteURL() bB3Mpaw@
{ /@R|*7K;9
return sSiteURL; _o~<f)E[9
} ].]yqD4P
"6^tG[G%
gg'lb{oG
public void setSSiteURL(String value) 9X,dV7 yW
{ Y oNg3
sSiteURL = value; T nAd!
} o4o&}
\hQ[5>
ncb?iJ/b^
public String getSFilePath() \
{ +N"A5U
return sFilePath; 5FtbZ1L
} zCL/^^#
[%YA42_`LD
=+~e44!~D
public void setSFilePath(String value) bM_Y(TgJ
{ f%ZqK_CW
sFilePath = value; [0yKd?e
} hEsCOcEG
YZ:YYcr
r1EccY
public String getSFileName() gR.zL>=_5e
{ t9&)9,my
return sFileName; \MsAdYR
} .oH0yNFX
u@}((V
T=:O(R1*0
public void setSFileName(String value) \:8~na+(
{ @Rj&9/\L
sFileName = value; =DvFY]9{
} dl'pl
e{:P!r aM
d,iW#,
public int getNSplitter() ( Z\OqG
{ 5,I'6$J
return nSplitter; 'Z+w\0}@
} %lbSV}V)
9bl&\Ykt.
Ah='E$t
public void setNSplitter(int nCount) +Qt=N6>
{ />Tyiy]2uu
nSplitter = nCount; i]Lt8DiRq
} `/f9 mn
} C 6Bh[:V&
2uZ <q?=
djS?$WBpU
/* b(_PCVC
**Utility.java (u@[}!
*/ .6xP>!E}Q
package NetFox; W tnZF]1:u
.UakO,"z
rhMsZ={M
public class Utility { t]P[>{y
ct3QtX0B
Ym(^ih
public Utility() m8rKH\FD}
{ g[@Kd
2JYp.CJv
f*Xonb
} i?z3!`m
Kw3fpNd
//线程睡眠 ^-w:D
public static void sleep(int nSecond) .S`Ue,H
{ "Fy34T0N
try{ >J[g)$,
Thread.sleep(nSecond); >"f,'S5*
} BXO(B'1)]
catch(Exception e) VE& ?Zd~
{ 'C1=(PE%`
e.printStackTrace (); ~&CaC
} 3Ku!;uo!u
} ] ^tor
AT<gV/1l
//日志 00Tm0rY
public static void log(String sMsg) sD1L P
{ SGZOfTcY
System.err.println(sMsg); A,W-=TC
} [VT&
{lT9gJ+
im>Sxu@
public static void log(int sMsg) ;tf1#6{
{ gd]vrW'wj
System.err.println(sMsg); FviLlly6
} -TU7GCb=
} Nb>|9nu O
%:h)8e-;
-9~kp'_a
/* L5(rP\B
**TestMethod.java 'jZ2^
*/ ;o,t*
package NetFox; LZMdW #,[
3%/]y=rA
.6!IO^`[
public class TestMethod { &0K;Vr~D
<&n3"
}Y(Q7l
public TestMethod() N6c']!aM@
{ ///xx/weblogic60b2_win.exe Nv,[E+a2
try{ $lOx 6rL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Dw%>y93V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mn{8"@Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); f~jx2?W
fileFetch.start(); l$z[Vh^UU<
} IPbdX@FeV
catch(Exception e){e.printStackTrace ();} rFM`ne<zh
Cnd*%CPZ
Z@nM\/vLA
} VCiJ]$`M
zid?yuP
#E2`KGCzW
public static void main(String[] args) bS3qX{5
{ KunK.m
new TestMethod(); $|C%G6!s?@
} yUq,9.6Ig
} 5{zXh
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