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)); N$#\Xdo
} iqPBsIW
for(int i=0;i<nEndPos.length-1;i++) QJBr6
{ MbA\pG'T
nEndPos = nStartPos[i+1]; 4 b,N8
} {x@|VuL=
nEndPos[nEndPos.length-1] = nFileLength; "rNL `P7
} SSA W52xC
} C5X(U:
/nQ`&q
q.V-LXM
//启动子线程 {y-^~Q"z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rRb+_]Lg
for(int i=0;i<nStartPos.length;i++) eUBrzoCO
{ ~ ?^/u8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Yj3I5RG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), XKU=oI0\j
nStartPos,nEndPos,i); <<zI\+V
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )^x K
fileSplitterFetch.start(); vhgLcrn
} |yY`s6Uq
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NNkP\oh\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); uY#TEjGh]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "![L#)"s
nEndPos = " + nFileLength); qJv[MBjk3B
// fileSplitterFetch[nPos.length-1].start(); E>uVofhml
{/8Q)2*>0
QP(BZJC
//等待子线程结束 (z7+|JE.
//int count = 0; `/IKdO*!S
//是否结束while循环 B[o`k]]
boolean breakWhile = false; kOrl\_!z3
!0}\&<8/m
WO*9+\[v
while(!bStop) LKF/u` 0dP
{ ^J/)6/TMXm
write_nPos(); zI;0&
Utility.sleep(500); WF2-$`x
breakWhile = true; 4P8*k[.
Jjm|9|C,
K[?Xm"4
for(int i=0;i<nStartPos.length;i++) n1v5Q2xw
{ g@ith&*=h
if(!fileSplitterFetch.bDownOver) [(mlv42"
{ 3iX?~
breakWhile = false; sRhKlUJG
break; *_-'/i
} j`>^1Q
} gP}+wbk
if(breakWhile) x3G:(YfO
break; L^`}J7r
CNrIIsJ
\XzM^K3
//count++; ~$,qgf
//if(count>4) 0 p uY"[c
// siteStop(); j?i#L}.I
} S?0$?w?
l.=p8-/$'7
K\?]$dK5
System.err.println("文件下载结束！"); uaPx"
} ^TdZ*($5
catch(Exception e){e.printStackTrace ();} ~N0sJ%
} V!/:53
z8_XX$Mnt
KOSM]c\H
//获得文件长度 YK#fa2ng
public long getFileSize() Dl\`
{ b1?xeG#
int nFileLength = -1; =d`5f@'rl
try{ *f+: <=i
URL url = new URL(siteInfoBean.getSSiteURL()); hGTV;eU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Xl-e !
httpConnection.setRequestProperty("User-Agent","NetFox"); :l\V'=%9'@
:l u5Uu~
O6s.<`\
int responseCode=httpConnection.getResponseCode(); iJh!KEy~A5
if(responseCode>=400) Sm{>rR
{ 5TKJWO.
processErrorCode(responseCode); Gu0 ,)jy\
return -2; //-2 represent access is error ^"8wUsP
} IVxWxM*N<
#s5N[uK^m
5g5'@vMN
String sHeader; <yUstz,Xu^
Q /x8 #X
>]D4Q<TY
for(int i=1;;i++) fPa9ofU/kr
{ ()T[$.(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K95;rd
//Utility.log(in.readLine()); BRRj$)u
sHeader=httpConnection.getHeaderFieldKey(i); R!\EKH
if(sHeader!=null) {Tp2H_EG
{ 2\D8.nQr
if(sHeader.equals("Content-Length")) ?uLeFD
{ f:JlZ&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Zo-$z8
break; '-$XX%TOAc
} %q3$|>
} .x83Ah`
else a6xj\w
break; k"UO c=
} jdA ]2]
} YNdrWBf)
catch(IOException e){e.printStackTrace ();} /7c~nBU
catch(Exception e){e.printStackTrace ();} g2cVZ!GIj
(t^n'V
PyC0Q\$%
Utility.log(nFileLength); X@N$Z{
jyS=!ydn+
>TL^>D
return nFileLength; hS [SRa'.
} alMYk
Z3KO90O!8
w&h2y4
//保存下载信息（文件指针位置） :;;E<74e i
private void write_nPos() =JLh?Wx
{ -;(Q1)&
try{ !v|ISyK
output = new DataOutputStream(new FileOutputStream(tmpFile)); {BBw$m,o
output.writeInt(nStartPos.length); W[bmzvJ_X
for(int i=0;i<nStartPos.length;i++) <Q< AwP
{ % ~]xuP[
// output.writeLong(nPos); +ZsX*/TOn
output.writeLong(fileSplitterFetch.nStartPos); -XK0KYhgW
output.writeLong(fileSplitterFetch.nEndPos); 's?Ai2=#
} I_)*)d44_
output.close(); B1 0+*p(
} "bQ[CD
catch(IOException e){e.printStackTrace ();} | $^;wP
catch(Exception e){e.printStackTrace ();} le)DgIT>=
} 9-1#( Y6S
CJknJn3m&
IakKi4(
//读取保存的下载信息（文件指针位置） MhEw _{?
private void read_nPos() 8ovM\9qT
{ \YJy#2K
try{ NW9n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ds8 EMtS
int nCount = input.readInt(); OKOu`Hz@
nStartPos = new long[nCount]; imL_lw^?
nEndPos = new long[nCount]; mg:!4O$K
for(int i=0;i<nStartPos.length;i++) 5~ 'Ie<Y_
{ :\~+#/=:
nStartPos = input.readLong(); ~ AQp|
nEndPos = input.readLong(); 9%)=`W
} J'&#mDU
input.close(); ]uL+&(cr
} L#[]I,
catch(IOException e){e.printStackTrace ();} Vn=qV3OE]
catch(Exception e){e.printStackTrace ();} dj6*6qX0'^
} R\Z:n*
&F$:Q:* *
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private void processErrorCode(int nErrorCode) ~`#-d ^s:
{ ;!@EixN-YH
System.err.println("Error Code : " + nErrorCode); FE7)E.U
} hv$yV%.`
8euZTfK9e
h #Z4pN8T3
//停止文件下载 Br>Fpe$q4
public void siteStop() >cmE t
{ #1-xw~_
bStop = true; DrW#v-d
for(int i=0;i<nStartPos.length;i++) *v%rMU7,
fileSplitterFetch.splitterStop(); .4.pJbOg
_1Z=q.sC
bEuaOBc
} X*oMFQgP
} <msxHw
//负责部分文件的抓取 RH;:9_*F
**FileSplitterFetch.java ?|;yVew
*/ _cDF{E+;
package NetFox; AF\T\mtvRm
M<?Q4a'Q
"R #k~R
import java.io.*; }_.:+H!@
import java.net.*; =wu*D5
)4Q?aMm
gW(gJ; L,%
public class FileSplitterFetch extends Thread { jZfx Jm
U4?(A@z9^
Q'apG)0I
String sURL; //File URL 9|'B9C
long nStartPos; //File Snippet Start Position Y o0FUj
long nEndPos; //File Snippet End Position (3vHY`9
int nThreadID; //Thread's ID -#`c5y}P
boolean bDownOver = false; //Downing is over 92W&x'
boolean bStop = false; //Stop identical Tm]nEl)_
FileAccessI fileAccessI = null; //File Access interface F-Z%6O,2
a.F Al@Br
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %6j)=IOts
{ TrVWv
this.sURL = sURL; $*[{J+t_
this.nStartPos = nStart; dBCbL.!
this.nEndPos = nEnd; |BMV.Zi
nThreadID = id; @# P0M--X
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vP!GJX&n5
} iSK+GQ~
D.!~dyI.,$
: DG)g3#
public void run() H( -Y
{ >/f_F6ay#
while(nStartPos < nEndPos && !bStop) PrF}a<:n:
{ D?jk$^p~m#
s)A<=)w/e
%u{W7
try{ kW3E =pr
URL url = new URL(sURL); igf)Hb;5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ha>*?`?yI
httpConnection.setRequestProperty("User-Agent","NetFox"); gv15t'y9
String sProperty = "bytes="+nStartPos+"-"; UK#&lim
httpConnection.setRequestProperty("RANGE",sProperty); 1xyU
Utility.log(sProperty); W3W'oo
}`VDD?M
JF9yVE-
InputStream input = httpConnection.getInputStream(); \b8sG"G
//logResponseHead(httpConnection); !#ri5{od
=Yo1v=wxN
eS/B24;*
byte[] b = new byte[1024]; {X]R-1>
int nRead; 9Vuq,dv
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pC,o2~%{
{ 2U kK0ls
nStartPos += fileAccessI.write(b,0,nRead); rf+:=|/_3
//if(nThreadID == 1) RNVbcd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &>WWzikB*
} "e3["'
"tit\a6\(
\h<BDk*
Utility.log("Thread " + nThreadID + " is over!"); x LBQ
bDownOver = true; 6Sj6i^"
//nPos = fileAccessI.write (b,0,nRead); ',7??Q7j&v
} ?VU(Pq*`
catch(Exception e){e.printStackTrace ();} oj,lz?
} FX<b:#
} }!#gu3
W" "*ASi
<3PL@orO
//打印回应的头信息 u),Qa=Wp
public void logResponseHead(HttpURLConnection con) TjK{9A
{ YKZrEP4^
for(int i=1;;i++) 7)rWw<mY
{ WnFG{S{s
String header=con.getHeaderFieldKey(i); NIr@R7MKd
if(header!=null) k`HP"H
//responseHeaders.put(header,httpConnection.getHeaderField(header)); bSwWszd~
Utility.log(header+" : "+con.getHeaderField(header)); ({0)@+V8
else v<\A%
break; " }gVAAvc7
} q}uHFp/J
} W_O)~u8
a\uie$"cr]
/T^ JS
public void splitterStop() F,Xo|jjj
{ Hk_y/97OO
bStop = true; v}G]X Z8
} z7.|fE)<6
_?7#MWe&
C9n}6Er=,
} 5pNY)>]t=
@(``:)Z<b
3XiO@jzre
/* =!Vf
**FileAccess.java "yziXT@V
*//文件访问(定位，写) d&cU*
package NetFox; SQsSa1
import java.io.*; %,@vWmn
?zJpD8e
/5AW?2)
public class FileAccessI implements Serializable{ 4W4kwU6D
q"KnLA(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T@wcHg
RandomAccessFile oSavedFile; :Br5a34q
long nPos; P=L$;xgp
|6:=}dE#[
$$i.O}
public FileAccessI() throws IOException .o%^'m"=D[
{ )o1eWL}
this("",0); j83? m
} {eJt,[Y *
X C86-b)E
5\mTr)\R
public FileAccessI(String sName,long nPos) throws IOException eC DIwB28
{ +`mGK:>
oSavedFile = new RandomAccessFile(sName,"rw"); ymY1o$qWB}
this.nPos = nPos; 5OIc(YhYf
oSavedFile.seek(nPos); K)7zKEp`cj
} MOn,Db$
A% Q!^d
(9\;A*CZ
public synchronized int write(byte[] b,int nStart,int nLen) {P9J8@D
{ e/_C
int n = -1; w"m+~).U
try{ 14eW4~Mr
oSavedFile.write(b,nStart,nLen); {>3\N0e5
n = nLen; |s7`F%
} )'4P.>!!aQ
catch(IOException e) rsn.4P=
{ (w(
e.printStackTrace (); RhI;;Y#@
} psh^MX)Q
yZ]:y-1
RT/o$$
return n; ,:Jus
} %\O#&=$E
tary6K9K+
,y`CRlr:
} =d 2r6%v
m .IU ;cR
#$~ba%t9%
/* r'LVa6e"N
**SiteInfoBean.java '[|+aJ
*/ zr v]
package NetFox; x}/,yaWZ
ql{(Lf$
Jo(`zuLJ
public class SiteInfoBean { 0X8t>#uF
Eh</? Qv\
s>_V
private String sSiteURL; //Site's URL Xm2\0=v5;
private String sFilePath; //Saved File's Path 8VG!TpX/B
private String sFileName; //Saved File's Name -W{DxN1
private int nSplitter; //Count of Splited Downloading File &K_)#v`|
Tl]e%A`|
$yDWu"R8
public SiteInfoBean() nL@KX>
{//nSplitter的缺省值为5 M4LP$N
//default value of nSplitter is 5 :,;K>l^U
this("","","",5); l:;PXy6)
} 'k;4j|<
B0$:b!
_CBWb
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `=+^|Y}
{ ]=rht9),"
sSiteURL= sURL; s..lK "b
sFilePath = sPath; c@[:V
sFileName = sName; WtQ8X|\`
this.nSplitter = nSpiltter; 4EI7W,y
%R#L
.xzEAu;
} {u{@jp
@}_WE,r
|@?%Ct
public String getSSiteURL() :a8 YV!X
{ OV2-8ERS
return sSiteURL; _LP/!D
} N- e$^pST
wHZW `
@Q&3L~K"
public void setSSiteURL(String value) I +5)Jau^S
{ )M=ioE8`h
sSiteURL = value; I&?Qq k
} |yyO q
%+ 7p lM
7g=2Z[o
public String getSFilePath() k$5 s{q
{ f:*vr['d
return sFilePath; G)#$]diNuX
} 1"8yLvtn
:(dHY
a8u9aEB
public void setSFilePath(String value) J]W5[)L
{ <9ig?{'
sFilePath = value; CO-_ea U(
} GWsE;
rqv))Zo`
{l_{T4xToB
public String getSFileName() NW~z&8L
{ c,so`I3rI
return sFileName; u$%t)2+$4
} ~pa!w?/bQ
IJTtqo
A,su;Qh
public void setSFileName(String value) YDC mI@
{ #QCphhG
sFileName = value; 64Lx-avf
} R [H+qr
Yw _+`,W
0![ +Q4"
public int getNSplitter() a{!QOX%K
{ pZ`|iLNl-
return nSplitter; jF`BjxrG
} h%WE=\,Qp
VxP&j0M>
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public void setNSplitter(int nCount) A5,t+8`aci
{ *5tO0_L
nSplitter = nCount; \txbhWN
} %h1N3\y9i(
} yx V:!gl
IUR<.Y`
t+oJV+@
/* &`b "a!
**Utility.java =4GSg1Biy
*/ ' |-JWH
package NetFox; 'mI'dG
|AZg*T3:W
yA{W
public class Utility { R+gz<H.Q
f3`7tA
2Q;9G6p
public Utility() V"cKJ;s
{ XdH\OJ
Q{e\}wN
:Xc@3gF
} O1')nYF7
zy*/T>{#
//线程睡眠 -}K<ni6
public static void sleep(int nSecond) 9&<x17'
{ B|o2K}%f
try{ BL@:!t
Thread.sleep(nSecond); T843":
} F~ Lx|)0M
catch(Exception e) (EPsTox
{ fs/*V~@
e.printStackTrace (); j}b\Z9)!
} QMv@:Eo
} lRh9j l
Uye|9/w8 !
//日志 W0I#\b18
public static void log(String sMsg) z;@*r}H
{ 9Fn\FYUq
System.err.println(sMsg); !8`3GX:B_
} SkU9ON
0M\D[mg
j,]Y$B
public static void log(int sMsg) ){jla,[
{ 8Lw B B
System.err.println(sMsg); mN8pg4
} F R|&^j6
} ~ T>U
Fl(T\-Eu
Ty88}V
/* D7_*k%;@
**TestMethod.java 8,dBl!G=
*/ O12eH
package NetFox; g+X}c/".
k4 F"'N
Cu6%h>@K$
public class TestMethod { $1SUU F\.
TX
SwZA6R&
public TestMethod() @JdZ5Q
{ ///xx/weblogic60b2_win.exe Haqm^Ky$
try{ >:lnt /N3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hB{jUP)";
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); YuB+k^
SiteFileFetch fileFetch = new SiteFileFetch(bean); S*yjee<@
fileFetch.start(); V59(Z
} kQ]$%Lk[
catch(Exception e){e.printStackTrace ();} ,@5I:X!rR
v+99 -.
F2X0%te
} RejQ5'Neh
K_&4D'
QY== GfHt
public static void main(String[] args) Y3Q9=u*5
{ 4j)tfhwd8
new TestMethod(); aMTu-hA
} \6\<~UX^
} qP<Lr)nUH
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