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)); -!cAr <
} b9N4Gr
for(int i=0;i<nEndPos.length-1;i++) o%%fO
{ ^!qmlx*
nEndPos = nStartPos[i+1]; 0)]1)z(P
} kk'w@Sn.(
nEndPos[nEndPos.length-1] = nFileLength; n:D*r$ C|p
} ,Tl5@RN
} .[fz x`
3>" h*U#
$rEd5W&d!
//启动子线程 jZ!JXmVV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eLny-.i,7
for(int i=0;i<nStartPos.length;i++) 0Y2^}u@5
{ [BBKj)IK
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F/SsiUBS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e;5Lv9?C8
nStartPos,nEndPos,i); 0AKwZ' &H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E3skC%}
fileSplitterFetch.start(); |mmG s
} He!!oKK>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A*~1Uz\t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lKUm_; m
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %},G(>
nEndPos = " + nFileLength); \2xBOe-a]
// fileSplitterFetch[nPos.length-1].start(); J\'5CG
rb'GveW[
jSYg\Z5!
//等待子线程结束 Ib8i#DV
//int count = 0; R TUNha^<T
//是否结束while循环 \q|PHl
boolean breakWhile = false; qo-F9u1J
f](uc(8Z
:5{@*
while(!bStop) k)V%.Eobf
{ U]0)$OH5e
write_nPos(); \]A;EwC4C
Utility.sleep(500); _vV&4>
breakWhile = true; vqOLSE"t*O
~!F4JRf
5I1J)K;
for(int i=0;i<nStartPos.length;i++) \{zAX~k6
{ bV*zMoD#
if(!fileSplitterFetch.bDownOver) A9Wqz"[
{ vfUfrk@D~
breakWhile = false; Gc!8v}[7J
break; s;7qNwYO
} %*c|[7Z~V
} (iOCzZ6S
if(breakWhile) dMmka
break; -QPWi2:k
u7&'3ef
5MY}(w
//count++; ;nKHm
//if(count>4) B8AzN9v&"N
// siteStop(); SM+fG:4d
} kdh9ftm*\
@1?]$?u&
[Cqqjv;_
System.err.println("文件下载结束！"); uQ]]]Z(H'
} 36x:(-GFq
catch(Exception e){e.printStackTrace ();} !5%5]9'n@*
} asN }
$>ZP%~O
s.^9HuM
//获得文件长度 hdtnC29$
public long getFileSize() \41)0,sEy
{ 2{B(j&{
int nFileLength = -1; |8c:+8
try{ prEu9$:t
URL url = new URL(siteInfoBean.getSSiteURL()); rk,1am:cg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g~c|~u(W
httpConnection.setRequestProperty("User-Agent","NetFox"); Tj21YK.mk
&s^>S?L-
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int responseCode=httpConnection.getResponseCode(); %y\eBfW,/
if(responseCode>=400) 72ViPWW
{ Kq 4<l
processErrorCode(responseCode); n_aNs]C9R
return -2; //-2 represent access is error ^b!7R <>~
} mH*@d"
2Uv3_i<
(vAv^A*i}
String sHeader; |1+(Ny.%k
L>Oy7w)Y
gJ5wAK+?
for(int i=1;;i++) bV$8 >[`
{ +#qt^NO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Bf:tal6 -M
//Utility.log(in.readLine()); i<wU.JX&h
sHeader=httpConnection.getHeaderFieldKey(i); B >u,)
if(sHeader!=null) MkW1FjdP
{ ,+/9K)X
if(sHeader.equals("Content-Length")) { w8 !K
{ ]\RSHz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {LT4u]#
break; Z-t}6c'Kg
} :-u-hO5*8
} `e?;vA&
else G?1x+H;o5
break; qTTn51
} 9R@abm,I
} ~+<xFi
catch(IOException e){e.printStackTrace ();} 2#b<d?"
catch(Exception e){e.printStackTrace ();} dT]L-uRZgy
!jAWNK6
jj3Pf>D+k
Utility.log(nFileLength); Q&upxE4-~
<DXmZ1
D#d8^U
return nFileLength; j!S1Y0CV
} w`j*W$82
[T4 pgt'H
VZ2.w4b
//保存下载信息（文件指针位置） Bzu(XQ
private void write_nPos() /1 US,
{ V9zywM
try{ ?..i4
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]PlY}VOY
output.writeInt(nStartPos.length); mX@j
for(int i=0;i<nStartPos.length;i++) mNx,L+3
{ jy!f{dsC
// output.writeLong(nPos); Eg`R|CF
output.writeLong(fileSplitterFetch.nStartPos); }$|%/Y
output.writeLong(fileSplitterFetch.nEndPos); JN&MyA"
} m)@Q_{=6M
output.close(); Mr=}B6`
} Na. nA
catch(IOException e){e.printStackTrace ();} KP=D! l&q
catch(Exception e){e.printStackTrace ();} t&R!5^R
} n9kd2[s|
|7QVMFZ
E 4='m
//读取保存的下载信息（文件指针位置） n5egKAgA
private void read_nPos() qSEB}1
{ 66~e~F}z
try{ wX)efLmyhY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $/[Gys3"
int nCount = input.readInt(); 3`&VRF8
nStartPos = new long[nCount]; e{fZ}`=7y
nEndPos = new long[nCount]; W>Mse[6`c
for(int i=0;i<nStartPos.length;i++) \;-=ODC
{ N<aB)</
nStartPos = input.readLong(); d&aBs++T
nEndPos = input.readLong(); #D`S
} S)"##-~`T
input.close(); ;Ze"<U
} 5jn$7iE`
catch(IOException e){e.printStackTrace ();} ?CH?kP
catch(Exception e){e.printStackTrace ();} 0NQ7#A
} {A]k%74-a
4ef*9|^x#
a9#W9eP
private void processErrorCode(int nErrorCode) 2f3=?YqD
{ v78&[
System.err.println("Error Code : " + nErrorCode); *>e~_{F
} |x d@M-ln
j:HH#U
nU}~I)@V
//停止文件下载 K4j@j}zK9I
public void siteStop() qs!>tw
{ kF+ZW%6N
bStop = true; ra]!4Kd'
for(int i=0;i<nStartPos.length;i++) Q&u>7_, Du
fileSplitterFetch.splitterStop(); Az U|p
'"` Lv/
968Ac}OA
} 4)c+t"h
} D3%l4.h
//负责部分文件的抓取 T@(6hEmP,
**FileSplitterFetch.java PSW#^o
*/ R'G'&H{N
package NetFox; xik`W!1S
} c{Fa&
=a?a@+
import java.io.*; gWFL
import java.net.*; UskZ%J
/GsSrP_?]
}US7Nw
public class FileSplitterFetch extends Thread { uyL72($
&}zRH}s;
=MMCf0
String sURL; //File URL HS{P?~:=U
long nStartPos; //File Snippet Start Position G3H#XK D
long nEndPos; //File Snippet End Position HjV\lcK:v
int nThreadID; //Thread's ID *I=_*LoG2
boolean bDownOver = false; //Downing is over azvDvEWCQZ
boolean bStop = false; //Stop identical N\_( w:q
FileAccessI fileAccessI = null; //File Access interface "YuZ fL`bb
dO+kPC
7k3p'FeS
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LL{t5(- _
{ PdR >;$1
this.sURL = sURL; Qqp)@uM^
this.nStartPos = nStart; PT mf
this.nEndPos = nEnd; 6yN" l Q7
nThreadID = id; %h0D)6j
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Am#m>^!qb
} c+1vqbqHG
LlU'_}>
'#H&:Htm;L
public void run() GUKDhg,W
{ wjuGq.qIu
while(nStartPos < nEndPos && !bStop) f](I.lm:
{ !0b%Jh
?4:rP@
6%>/og\%
try{ _~ v-:w
URL url = new URL(sURL); !2(.$}E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Cq gJ
httpConnection.setRequestProperty("User-Agent","NetFox"); yP x\ltG3
String sProperty = "bytes="+nStartPos+"-"; ]+AAT=B<!
httpConnection.setRequestProperty("RANGE",sProperty); Y]~IY?I
Utility.log(sProperty); Bk+{}
H]BAW*}
SAP;9*f1\
InputStream input = httpConnection.getInputStream(); 8AryIgy>@
//logResponseHead(httpConnection); #`vVgGZ&
658\#x8|
p[u4,
byte[] b = new byte[1024]; C+`xx('N9
int nRead; .XIr?>G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) THJ 3-Ug
{ Axf^hBP
nStartPos += fileAccessI.write(b,0,nRead); l7ZB3'
//if(nThreadID == 1) Ex6o=D2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @2u#93Y
} D{>\-]\
t7&Dwmck9
sqT^t!
Utility.log("Thread " + nThreadID + " is over!"); 3#9uEDdE
bDownOver = true; RXM}hqeG
//nPos = fileAccessI.write (b,0,nRead); WI6(#8^p
} >ZX|4U[$P
catch(Exception e){e.printStackTrace ();} jSB'>m]
} 1ADv?+j)A/
} ^L ]B5,}-
NK~PcdGl
k9l^6#<?
//打印回应的头信息 *=TYVM9
public void logResponseHead(HttpURLConnection con) xLZbU4
{ ZlrhC= 0
for(int i=1;;i++) s*f1x N<
{ qT$)Rb&
String header=con.getHeaderFieldKey(i); Y5n>r@)m
if(header!=null) c88_}%h?(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8|6~o.B.G
Utility.log(header+" : "+con.getHeaderField(header)); f -7S:,
else >zFD$
break; Y!M~#oqio
} 6i| ~7md,
} w?_`/oqd|
O)`Gzx*ShU
.wD>Gs{sH[
public void splitterStop() }Fm\+JOS
{ L$SMfx
bStop = true; 7u|%^Ao6
} [T-*/}4$
bH,M,xIL2
s@PLS5d"
} j-QGOuvW
Wa<-AZnh
D&-vq,c
/* e:BDQU
**FileAccess.java c`ftd>]
*//文件访问(定位，写) :s]\k%"
package NetFox; **n y!
import java.io.*; )%t7\1)B3
:WO{xg
e+{BJN vz
public class FileAccessI implements Serializable{ lA]N04 d
_CL{IY
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 qW3x{L$c
RandomAccessFile oSavedFile; }1Z6e[K?
long nPos; tJAnuhX
L?Cjo4xS
l/QhD?)9
public FileAccessI() throws IOException &y\igX1
{ (Igu:=
this("",0); #n#HzbT
} 9OfU7_m
9>;} /*:H
ZL,8,;]
public FileAccessI(String sName,long nPos) throws IOException [1U{ci&=p
{ "O``7HA}
oSavedFile = new RandomAccessFile(sName,"rw"); y] y9'5_
this.nPos = nPos; Hr&Ere8.4p
oSavedFile.seek(nPos); E?_ zZ2
} Wt:~S/l
+<{m45
%i595Ij-]
public synchronized int write(byte[] b,int nStart,int nLen) a5 bPEJ=I
{ Cdmy.gx^
int n = -1; :]-$dEu&
try{ KGD'mByt"
oSavedFile.write(b,nStart,nLen); w,/6B&|
n = nLen; mqw 84u
} \C7q4p?8
catch(IOException e) zIm-X,~I$
{ pZjpc#*9N
e.printStackTrace (); =9<$eLE0
} \?dTH:v/E
nd.hHQ
7 OWsHlU
return n; *E7R(#,yC
} ,_bp)-OG
xh r[A
}#bZ8tm&
} 7O$ &
>4c`UW
&oEyixe
/* %N1"*</q
**SiteInfoBean.java djGs~H>;U_
*/ cWM:
package NetFox; 5NFRPGYX
a%*_2#
0MrN:M2B
public class SiteInfoBean { ^vM_kArA
1]Lh'.1^
P7UJ-2%Y+
private String sSiteURL; //Site's URL x0ne8NDP
private String sFilePath; //Saved File's Path Why"G1`
private String sFileName; //Saved File's Name f"P$f8$
private int nSplitter; //Count of Splited Downloading File ]!faA\1
Zw24f1iY
8i[LR#D)
public SiteInfoBean() N|<bVq%
{//nSplitter的缺省值为5 [T]Bfo
//default value of nSplitter is 5 5k~\or 5_
this("","","",5); m9!DOL1pl
} A_F0\ EN*
}*Zo6{B-
- wWRm
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B\0t&dai|'
{ Eu4 &-i
sSiteURL= sURL; zi.mq&,]R
sFilePath = sPath; x`L+7,&n
sFileName = sName; E-F5y
this.nSplitter = nSpiltter; WUY,. 8
RY<%'\A`~
[xf$VkjuF
} `M0YAiG
( OXY^iq
p[Hr39o
public String getSSiteURL() Fv@tD4I>
{ 6klD22b2$
return sSiteURL; HzEGq,.
} ^/<|f,2
)#PtV~64
=y<0UU
public void setSSiteURL(String value) j%WY ,2P
{ Ro~fvL~Ps
sSiteURL = value; 10O3Z9
} 63C(Tp"
PkO!'X
ll2Vk*xs
public String getSFilePath() ZRPy~wy>
{ j.B>v\b_3
return sFilePath; f~R[&q+
} 0R4akLW0
&~ y{'zoL
*v&*% B
public void setSFilePath(String value) }H2#H7!H
{ 8JP6M!F#
sFilePath = value; FJF3B)Va|
} ~QCA -Yud
RJwb@r<v
8$m1eQ`{
public String getSFileName() b}}y=zO|$
{ v8
return sFileName; \OA L Or
} vnZ4(
dE GX3 -
&+]x;K
public void setSFileName(String value) }PmTR4F!}
{ o X@nP?\
sFileName = value; N3Z@cp
} yf?W^{^|
^}hZ'<PK
I{EIHD<
public int getNSplitter() ?b"Vj+1:x
{ m/{Y]D{2
return nSplitter; ,ex]$fQ'
} 1J&#&\,f&
BCBUb
#fN/LO
public void setNSplitter(int nCount) L^)qe^%3
{ C/
nSplitter = nCount; zhjJ>d%w
} zWtj|%ts
} 9cz)f\
zuMO1s
7jT#BWt
/* E[ 0Sst x
**Utility.java _jo$)x+'x
*/ oSmjs
package NetFox; <"A#Eok|4
wx./"m.M
WAv@F[
public class Utility { ?Nu#]u-
NZfd_? 3
'QR4~`6I
public Utility() ET3,9+Gj
{ j3LNnZY
0R*}QXph
NN11}E6
} GZS{&w!
ey*,StT5a
//线程睡眠 77tZp @>hn
public static void sleep(int nSecond) ]`K[W&
{ <ZV7|'^
try{ WSS(Bm|B
Thread.sleep(nSecond); sSV^5
} H6{Rd+\Z
catch(Exception e) QY=QQG
{ Yx!n*+:J
e.printStackTrace (); 'z~KTDX
} N" ;^S
} g4Bg6<;
}-dF+m:
//日志 v|>BDN@,6
public static void log(String sMsg) tpE3|5dZF
{ =uS8>.Qj
System.err.println(sMsg); TtZrttCE6
} 7F~xq#Wi#
j~.u>4
jWhD5k@v
public static void log(int sMsg) yG4MUf6
{ F; 0Dp
System.err.println(sMsg); ^&HI+M
} X!m;uJZp
} oR77`
u$\Tg3du2
~O8]3+U
/* >H8^0n)?
**TestMethod.java |]I#CdO
*/ ,d5ia4\K
package NetFox; nMeSCX
I ;l`VtD
fq{I$syY
public class TestMethod { 2AmR(vVa"
(Y&R0jt
=w t-YM
public TestMethod() JLt{f=`%F
{ ///xx/weblogic60b2_win.exe L-SdQTx_
try{ ]2g5Ka[>w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X9SJ~n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); aL{EkiR
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5t TLMZ`o
fileFetch.start(); j_hjCQ
} oA[2)BU
catch(Exception e){e.printStackTrace ();} - f+CyhR"*
k#BU7Exij
uLF\K+cz
} 3$;J0{&[i
N c9<X
Ogn,1nm%
public static void main(String[] args) oK%K+h
{ /]P%b K6B
new TestMethod(); 3KbUHSx
} ~rp.jd 0l
} >Y44{D\`
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