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)); _^ |2}t
} [k%4eO2p"
for(int i=0;i<nEndPos.length-1;i++) ,<Kx{+ [h
{ i@P}{
nEndPos = nStartPos[i+1]; j?i#L}.I
} S?0$?w?
nEndPos[nEndPos.length-1] = nFileLength; oF&l-DHp
} ,. EBOUW^
} #ToK$8
au@a8MP
<i. apBH
//启动子线程 {S.>BXX
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {]N3f[w
for(int i=0;i<nStartPos.length;i++) L,_.$1d
{ a[!%Ld
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {8RFK4! V@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b1?xeG#
nStartPos,nEndPos,i); =d`5f@'rl
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t*S." q
fileSplitterFetch.start(); hGTV;eU
} *C|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^s:y/Kd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >l5$9wO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6<'K~1do:
nEndPos = " + nFileLength); &2.u%[gO[q
// fileSplitterFetch[nPos.length-1].start(); (R}ii}&
5TKJWO.
'DbMF?<.
//等待子线程结束 OS-f(qXd+
//int count = 0; 3`.P'Fh(k
//是否结束while循环 4@3[
boolean breakWhile = false; % ZU/x d
0#p/A^\#7M
Wd,a?31|
while(!bStop) )6X.Nfkb^k
{ P5<vf
write_nPos(); aoW6U{\
Utility.sleep(500); <yUstz,Xu^
breakWhile = true; Yl cbW0'c
V*[b}Xew
k ]a*&me
for(int i=0;i<nStartPos.length;i++) [\z/Lbn ,.
{ fPa9ofU/kr
if(!fileSplitterFetch.bDownOver) $4=f+ "z
{ RVw9Y*]b
breakWhile = false; 2'0K WYM
break; uKr1Z2
} |AZW9
} mh/n.*E7
if(breakWhile) R!\EKH
break; 3,X/,'
:Ixx<9c.
2h=%K/hhY
//count++; HfNDD|Zz
//if(count>4) ^ZRYRA
// siteStop(); W6c]-pc
} +K",^6%1
/B3R1kNf|
^C)n$L>C0
System.err.println("文件下载结束！"); a}yXC<}$
} g=@_Z"
catch(Exception e){e.printStackTrace ();} %q3$|>
} !RvRGRSyF
.x83Ah`
Pt,ebL~
//获得文件长度 r),PtI0X
public long getFileSize() sN=6gCau
{ >p\e0n
int nFileLength = -1; )(M7lq.e7
try{ %:v`EjRD0
URL url = new URL(siteInfoBean.getSSiteURL()); =qVP] 9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [tT8_}v$LN
httpConnection.setRequestProperty("User-Agent","NetFox"); LaFZ?7@|}
22hSove.
V<Z'(UI
int responseCode=httpConnection.getResponseCode(); -T@`hk`
if(responseCode>=400) ~EiH-z4U
{ n||A" @b\
processErrorCode(responseCode); s54nF\3V
return -2; //-2 represent access is error UPU+ver
} 2!1.E5.I
zt24qTKL
k3!a$0Bs;
String sHeader; /a9!Cf
n 1b(\PA
Z3KO90O!8
for(int i=1;;i++) XUMX*
{ w&h2y4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ed 59B)?l
//Utility.log(in.readLine()); Q[n\R@
sHeader=httpConnection.getHeaderFieldKey(i); 3Mjj'5KH!
if(sHeader!=null) 6c4&VW
{ 'fV%Z
if(sHeader.equals("Content-Length")) SUCUP<G
{ 9Ru;`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /lhz],w
break; }Rvm &?~O
} j1$8#/r;c
} RF}X ER
else |`k .y]9
break; <E|s\u
} ^y.nDs%ZT7
} q-$`k
catch(IOException e){e.printStackTrace ();} Pf_F59"
catch(Exception e){e.printStackTrace ();} 5i6 hp;=
>B -q@D
M6|I6M<
Utility.log(nFileLength); 5E\#%K[
+YY8h>hj
83~ i:+;
return nFileLength; pcS+o
} @ T;L$x
FwAKP>6*
\BV 0zKd
//保存下载信息（文件指针位置） U 5w:"x
private void write_nPos() z$lF)r:Bc
{ w?vVVA
try{ 5MTgK=c
output = new DataOutputStream(new FileOutputStream(tmpFile)); Lm*VN~2
output.writeInt(nStartPos.length); . v)mZp
for(int i=0;i<nStartPos.length;i++) 0BPMmk
{ &[R8Q|1j
// output.writeLong(nPos); 8^^[XbH
output.writeLong(fileSplitterFetch.nStartPos); MhEw _{?
output.writeLong(fileSplitterFetch.nEndPos); !eR3@%4
} r{Rg920
output.close(); yTM3^R(
} {QaNAR=)
catch(IOException e){e.printStackTrace ();} P,pnga3Wu
catch(Exception e){e.printStackTrace ();} 8OhDjWVJ
} 7k%T<;V
5ABhj*7
[dX`K`k
//读取保存的下载信息（文件指针位置） z2c5m
private void read_nPos() yqOuX>m1c
{ e&q?}Ho
try{ 7^TV~E#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); faXx4A2"
int nCount = input.readInt(); 4NR@u\S
nStartPos = new long[nCount]; G\gMC <3
nEndPos = new long[nCount]; /?-7Fg+,
for(int i=0;i<nStartPos.length;i++) :&XH?/Wi
{ u`:hMFTID
nStartPos = input.readLong(); 0[A9b,MMVO
nEndPos = input.readLong(); (P|~>k
} t/oN>mQG
input.close(); "VxWj}+]
} cS.i
catch(IOException e){e.printStackTrace ();} w)]H ^6
catch(Exception e){e.printStackTrace ();} Bvjl-$m!v
} Oc?+M 5
&p UZDjo?
R>@uY(>dJ
private void processErrorCode(int nErrorCode) Vn=qV3OE]
{ Q/>L_S
System.err.println("Error Code : " + nErrorCode); 2GmpCy`L"
} S]3Ev#>
R\Z:n*
ov#7hxe
//停止文件下载 qF)<H
public void siteStop() 7Du1RuxP
{ ]<uQ.~
bStop = true; R5_i15<
for(int i=0;i<nStartPos.length;i++) 8[%Ao/m
fileSplitterFetch.splitterStop(); K!AAGj`
/(C~~XP)
7sNw
} d^ ZMS~\*
} ^}yg%+
//负责部分文件的抓取 %WFu<^jm
**FileSplitterFetch.java S*)1|~pRvQ
*/ E N^Uki`
package NetFox; RuW!*LI
r}_c
'Yy&G\S
import java.io.*; !|?e7u7
import java.net.*; ) iQ
_>o-UBb4]T
gieJ}Bv
public class FileSplitterFetch extends Thread { ]1-z!B4K
M&Y .;
tCF&OOI4`
String sURL; //File URL 0"k|H&
long nStartPos; //File Snippet Start Position [p r"ZQ]
long nEndPos; //File Snippet End Position Y]`.InG@
int nThreadID; //Thread's ID f2)XP$:
boolean bDownOver = false; //Downing is over he3SR@\T
boolean bStop = false; //Stop identical rd|uz4d
FileAccessI fileAccessI = null; //File Access interface y? (2U6c
Ma-\^S=
QvPD8B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wt}9B[
{ 5-u=o)>
this.sURL = sURL; \Xrw"\")j
this.nStartPos = nStart; &.i^dO^}
this.nEndPos = nEnd; IputF<p
nThreadID = id; LS>G4 ]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =8G&3 R
} BG2)v.CU
Q'B6^%:<~
?@6b>='!
public void run() 5 +9Ze9
{ :bU(S<%M
while(nStartPos < nEndPos && !bStop) Ac k}QzXO
{ :HViX:]H
+~Cy$MCX
/x@RNdKv
try{ c2SC|s]
URL url = new URL(sURL); DmqX"x%P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zRl~^~sY
httpConnection.setRequestProperty("User-Agent","NetFox"); <g8K})P
String sProperty = "bytes="+nStartPos+"-"; (AY9oei>
httpConnection.setRequestProperty("RANGE",sProperty); "L"150Ih
Utility.log(sProperty); *mG`_9
Z5G!ct:W
(3vHY`9
InputStream input = httpConnection.getInputStream(); &7?R+ZGo
//logResponseHead(httpConnection); DsDzkwJE
z;u> Yz+3
0CvsvUN@
byte[] b = new byte[1024]; t/i5,le
int nRead; C2e.2)y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %n0;[sD0A
{ UnWW/]E
nStartPos += fileAccessI.write(b,0,nRead); T0HuqJty
//if(nThreadID == 1) W\*-xf|"d
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }b3/b
} 1-SVCk -
\~rlgxd
"+"{+k5t
Utility.log("Thread " + nThreadID + " is over!"); "GT4s?6O
bDownOver = true; &FdWFt=X
//nPos = fileAccessI.write (b,0,nRead); gA#RM5x@
} dBCbL.!
catch(Exception e){e.printStackTrace ();} |BMV.Zi
} Rxpn~QQ
} K2_Qu't0$
mumXUX
VUU]Pu &
//打印回应的头信息 4tA_YIv
public void logResponseHead(HttpURLConnection con) Die-@z|Y
{ $ls[|N:y0l
for(int i=1;;i++) ?q2j3e[>
{ qgt[~i*
String header=con.getHeaderFieldKey(i); 3{Nbp
if(header!=null) :)f7A7:;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); pfuW
Utility.log(header+" : "+con.getHeaderField(header)); Lr;(xw\['
else z~6y+
break; Lju7,/UD
} UQCo}vM
} k?nQ?B W
w-B^ [<
R
public void splitterStop() Q }k.JS~#
{ 8Chj w wB
bStop = true; !4@G3Ae22
} #4LFG\s
~Z/ ^c,[:
U09.Y
} q=HHNjj8
+H/jK@
7"X>?@
/* 4S0>-?{
**FileAccess.java F7m?xy
*//文件访问(定位，写) ge3sU5iZ
package NetFox; >r/rc`Q
import java.io.*; XhzGLYb~I`
txql 2
Cm$1$?J
public class FileAccessI implements Serializable{ +#@"*yj3
.k{ j]{k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 N<|$h5isq
RandomAccessFile oSavedFile; 2g{)AtK$#
long nPos; vY|^/[x#B
p4>$z& _
#h!*dj"
public FileAccessI() throws IOException \/7i-B]G7
{ oz'\q0
this("",0); Ey{%XR+*;
} 1iT\df
6Z?j AXGSq
31+;]W=
public FileAccessI(String sName,long nPos) throws IOException n@C~ev@%S
{ {@}?k s5
oSavedFile = new RandomAccessFile(sName,"rw"); .Jb$l$5'w
this.nPos = nPos; b<I9 MR
oSavedFile.seek(nPos); Rr(* aC2P
} +!-~yf#RE
h~U02"$
~\nBjM2
public synchronized int write(byte[] b,int nStart,int nLen) cR-~)UyrO
{ z7.|fE)<6
int n = -1; _?7#MWe&
try{ C9n}6Er=,
oSavedFile.write(b,nStart,nLen); jt~Qu-
n = nLen; :^ i9]
} g3@Rl2yQJ
catch(IOException e) 3b'tx!tFN
{ M_0zC1
e.printStackTrace (); 1xNVdI
} :R6bq!
,[p T4G
bok.j
return n; <BWkUZz\P|
} pZZgIw}aS
j;yf8Nf
&MR/6"/s
} z9 u$~
D;GD<zC]
qVjWV$j
/* 5lKJll^2:
**SiteInfoBean.java %ugHhS!
*/ MJ<Jb,D1
package NetFox; =6FUNvP#8
z><5R|Gf
o{v&.z
public class SiteInfoBean { +1C3`0(
Ph&urxH@
P27%xV-n>
private String sSiteURL; //Site's URL T[k4lM
private String sFilePath; //Saved File's Path C;AA/4Ib
private String sFileName; //Saved File's Name y #f QPR
private int nSplitter; //Count of Splited Downloading File :_<_[Y]1
ukgAI<O%
zHWSE7!
public SiteInfoBean() ?B@;QjhjiJ
{//nSplitter的缺省值为5 zxb/
//default value of nSplitter is 5 i[C~5}%
this("","","",5); 'PZ|:9FX!
} 9DQ)cy
TjWE_Bq]g
DVZdClAL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) GJi~y
{ 05Fz@31~
sSiteURL= sURL; 148V2H)
sFilePath = sPath; QZAB=rR
sFileName = sName; 9A,Z|q/z5
this.nSplitter = nSpiltter; RhI;;Y#@
psh^MX)Q
4PLk
} ,:Jus
%\O#&=$E
tary6K9K+
public String getSSiteURL() ,y`CRlr:
{ h<<>3A
return sSiteURL; #mR4fst
} Mk<Vydds
lLq<xf
.%BT,$1K
public void setSSiteURL(String value) Mk 0+D#
{ 8eIUsI.o
sSiteURL = value; +'@+x'/{^
} h!@|RW&}qX
<^.=>Q0S\
}_tln
public String getSFilePath() `cz2DR-"
{ KAA-G2%M
return sFilePath; n>3U_yt6b
} V!%jf:k
IH48|sa
~\p]~qQ\K
public void setSFilePath(String value) ] H~4
{ b2(RpY2Y
sFilePath = value; a?} .Fs
} zIC;7 5#
8kE]_t
;DA8B'^>
public String getSFileName() e<7.y#L
{ +=Jir1SLV
return sFileName; $w)~O<_U
} MfO:m[s
7`vEe'qz
O-]mebTvw
public void setSFileName(String value) G2 ]H6G$M
{ !J1rRPV
sFileName = value; _cTh#t ^
} :Eh\NOc_O
DBLk!~IF
*,C(\!b !?
public int getNSplitter() 7 J^rv9i4
{ q>f<u&
return nSplitter; (z7vl~D
} rt3qdk5U
# ?1Sm/5k`
[P zv4+
public void setNSplitter(int nCount) rD?L
{ 2n><RZ/9
nSplitter = nCount; =@Dwlze
} -50HB`t
} *D4hq=
V6$xcAE"</
0`.^MC?
/* @J{m@ji{
**Utility.java AWjJ{#W>9
*/ 'K@|3R
package NetFox; G)#$]diNuX
{^CT}\=>
UX-&/eScN
public class Utility { nMDxH$O
rWys'uc
&uP~rEJl+
public Utility() o)6pA^+
{ h1 WT
sAo& uZ
W)'*m-I
} QY/hI`
DU%w1+u
//线程睡眠 1}hIW":3Sr
public static void sleep(int nSecond) 4%WzIzRb
{ _(J&aY\
try{ g&dPd7
Thread.sleep(nSecond); IcP)FB4
} 4=uhh
catch(Exception e) 64Lx-avf
{ AE: Z+rM*
e.printStackTrace (); r|4t aV&
} j Ja$a [
} Nu8Sr]p
=_j vk.
//日志 8eA+d5k\.
public static void log(String sMsg) Vz14j_
{ %1pYEHn
System.err.println(sMsg); "~UUx"Y
} T0)4v-EO
js1!9%BV
y"]n:M:(
public static void log(int sMsg) y(R? ,wa=]
{ nEzf.[+9/
System.err.println(sMsg); mw_Ew]&
} *5bLe'^\|K
} Y_`-9'&
!=;XBd-
aA7=q=
/* R.7:3h
**TestMethod.java [m^+,%m5]
*/ XC{eX&,2x
package NetFox; \~P=U;l=pO
(}.@b|s
Y*_)h\f
public class TestMethod { <2C7<7{7
A!1;}x
q&C""!h^
public TestMethod() !4]9!<.k
{ ///xx/weblogic60b2_win.exe kyR*D1N&)
try{ jYNrD"n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); </uOe.l>Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >-&R47G
SiteFileFetch fileFetch = new SiteFileFetch(bean); E.1J2Ne
fileFetch.start(); MX@IHc
} >#ZUfm{k$
catch(Exception e){e.printStackTrace ();} ^ 9!!;)
h|X^dQb]
$d?.2Kg
} ;?C#IU
9@Cv5L?p\
Uye|9/w8 !
public static void main(String[] args) W0I#\b18
{ Spt?>sm
new TestMethod(); @p\}pY$T
} 5zON}"EC
} 8p[)MiC5W^
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