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)); )yS8(F0
} 8 LsJ}c
for(int i=0;i<nEndPos.length-1;i++) OOzXA%<%c
{ BKu<p<
nEndPos = nStartPos[i+1]; _hEr,IX=J
} ]x6rP
nEndPos[nEndPos.length-1] = nFileLength; c>wne\(5H
} v R! y#
} @[]#[7
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2FEi-m}
//启动子线程 w+hpi5OH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [f=Y*=u9,
for(int i=0;i<nStartPos.length;i++) 1/c+ug!y
{ "FLiSz%ME
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K/8TwB?I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I\|.WrMNi
nStartPos,nEndPos,i); cPX^4d~9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >&Y\g?Z6G
fileSplitterFetch.start(); L!~ap
} 0_-P~^A
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'v5q/l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B\+uRiD8w
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~g*5."-i
nEndPos = " + nFileLength); ;G*)7fi
// fileSplitterFetch[nPos.length-1].start(); k!d<2Qp W
l_zTpyOZ
2FR5RG oD
//等待子线程结束 t_\&LMD
//int count = 0; H"wIa8A
//是否结束while循环 Rp6q)
boolean breakWhile = false; =|H.r9-PK6
}w{E<C(M
x}#N?d
while(!bStop) [x -<O:r=P
{ {N@Pk[!
write_nPos(); G}@a]EGm
Utility.sleep(500); )g`~,3G
breakWhile = true; ~Sx\>wBlc
6ck%M#v
6u{%jSA>D\
for(int i=0;i<nStartPos.length;i++) ]6,D9^{;
{ i$CF*%+t
if(!fileSplitterFetch.bDownOver) ;dTxQ_:
{ bl#6B.*=
breakWhile = false; %Hu.FS5'
break; rv2;)3/*
} v(P <_}G
} m1M6N`f
if(breakWhile) 6+:;Mb_S
break; 593!;2/@
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Ei89Ngp\}
//count++; 3Qu-X\
//if(count>4) T[2<_nn=
// siteStop(); C{,Vk/D-0
} T75N0/teS
4K,S5^`Gx
ts r{-4V
System.err.println("文件下载结束！"); o+Q2lO5
} SUD~@]N1
catch(Exception e){e.printStackTrace ();} q XB E3
} ~w}=Oby'y
<|hrmwk|
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//获得文件长度 SME]C')7
public long getFileSize() c,#Nd@
{ DH:9iX'
int nFileLength = -1; Ti>}To}B5
try{ Ho $+[K
URL url = new URL(siteInfoBean.getSSiteURL()); kH4m6p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gZ=$bR
httpConnection.setRequestProperty("User-Agent","NetFox"); R#s_pW{op
lHE+o;-
[C@Ro,mI
int responseCode=httpConnection.getResponseCode(); \p!m/2
if(responseCode>=400) l|M|;5TW
{ }Ggn2 X
processErrorCode(responseCode); _WI~b
return -2; //-2 represent access is error ZHCrKp
} A>\3FeU>UC
(R(NEN
NWj4U3x
String sHeader; !p_l(@f
zo@,>'m
gBZNO! a,d
for(int i=1;;i++) .I%B$eH
{ f4vdJ5pV
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cG4}daK]d
//Utility.log(in.readLine()); BRv#`
sHeader=httpConnection.getHeaderFieldKey(i); CjJ n
if(sHeader!=null) !$<Kp6
{ >L$9fn/J
if(sHeader.equals("Content-Length")) P=X)Ktmv
{ SKGnx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !e('T@^u6u
break; ?\zyeWK0L
} boZ/*+t
} bG+Gg*0p
else IEWl I
break; ,2P/[ :
} ^Zlbs goZ
} m;PTO$--
catch(IOException e){e.printStackTrace ();} ^BP4l_rO9
catch(Exception e){e.printStackTrace ();} 'Y]<1M>.g
n,{
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Utility.log(nFileLength); GqgJ]m
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return nFileLength; %h v-3L#V
} R9UC0D:-x
^c|0?EH
m~F ~9&
//保存下载信息（文件指针位置） |RDE/
private void write_nPos() M`xI N~
{ 4thPR}DH}
try{ `R*!GHro
output = new DataOutputStream(new FileOutputStream(tmpFile)); jEK{47i v
output.writeInt(nStartPos.length); 2 S2;LB
for(int i=0;i<nStartPos.length;i++) ,/[1hhP@
{ OOYdrv,
// output.writeLong(nPos); Vc+~yh.)
output.writeLong(fileSplitterFetch.nStartPos); ,,-j5Y
output.writeLong(fileSplitterFetch.nEndPos); M->#WGl\B
} ZL9|/ PY
output.close(); ,.&D{$1W
} o@YEd d
catch(IOException e){e.printStackTrace ();} r$%,k*X^ k
catch(Exception e){e.printStackTrace ();} Kc+9n%sp
} 5"D\n B%
Ef=4yH?\j
{6F]w_\
//读取保存的下载信息（文件指针位置） {7Kl#b
private void read_nPos() '@"A{mrE
{ RI BB*
try{ +:u &]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); NSQ)lSW,;
int nCount = input.readInt(); M*dou_Q
nStartPos = new long[nCount]; Qd}h:U^
nEndPos = new long[nCount]; Z-aB[hE
for(int i=0;i<nStartPos.length;i++) Q|f)Awe$
{ :kXxxS
nStartPos = input.readLong(); zF&_9VNk=c
nEndPos = input.readLong(); q\Z9.T+Qo
} %@%~<U)W
input.close(); ;!EEzR.
} ppO!v?
catch(IOException e){e.printStackTrace ();} *k0;R[IAV
catch(Exception e){e.printStackTrace ();} aI\]R:f,
} Hlj3z3
qtp-w\#S$
C(}Kfi@6N
private void processErrorCode(int nErrorCode) n'@XgUI,
{ Rtai?
System.err.println("Error Code : " + nErrorCode); ~P9^4
} EtDzmpJR>
O! w&3 p
`>`{DEDx{5
//停止文件下载 EHt(!;?q
public void siteStop() &y~GTEP
{ p0HcuB)Y
bStop = true; #twl
for(int i=0;i<nStartPos.length;i++) X&,a=#C^
fileSplitterFetch.splitterStop(); 5WI0[7
Chtls;Ph[
ET|4a(x
} NaeG)u#+
} S?Uvt?
//负责部分文件的抓取 jDW$}^ 6
**FileSplitterFetch.java {!"lHM%
*/ (@xr/9:i
package NetFox; S#|5&SR
|l,0bkY@&
SuA`F|7?P
import java.io.*; Gdlx0i
import java.net.*; r D|Bj(X8
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OWmI$_L
public class FileSplitterFetch extends Thread { QC+BEN$
58Z,(4:E
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String sURL; //File URL 7[(<t+
long nStartPos; //File Snippet Start Position G3t\2E9S
long nEndPos; //File Snippet End Position `R:HMO[ow
int nThreadID; //Thread's ID 9Oc(Gl5az
boolean bDownOver = false; //Downing is over -[7S.
boolean bStop = false; //Stop identical h>n<5{zqM
FileAccessI fileAccessI = null; //File Access interface k7bfgb{
3yM!BTlX
"C]_pWk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _^Q =n>G
{ 1$uO%
this.sURL = sURL; 9K#U<Q0b'
this.nStartPos = nStart; )7iYx{n
this.nEndPos = nEnd; (M,*R v
nThreadID = id; .p\<niu7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C-VkXk
} }_cX" s
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C?PgC~y)
public void run() +p &$`(
{ {IQCA-AI
while(nStartPos < nEndPos && !bStop) WSV% Oy3V
{ ~`VD}{[,B
=%d0MZD
3HB(rTw
try{ Ndqhc
URL url = new URL(sURL); W$u/tRF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3?yq*uE}
httpConnection.setRequestProperty("User-Agent","NetFox"); .KE2sodq
String sProperty = "bytes="+nStartPos+"-"; c+]5[6
httpConnection.setRequestProperty("RANGE",sProperty); +q)B4A'J!
Utility.log(sProperty); EP]OJ$6I
l1}HJmom
o%?~9rf]]
InputStream input = httpConnection.getInputStream(); M\bea
//logResponseHead(httpConnection); 8f-B-e?k
RQd5Q.
~@EBW3>~5
byte[] b = new byte[1024]; Rs1JCP=d8
int nRead; "\x\P)j0>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2]-xmS>|b
{ `Z~\&r=
nStartPos += fileAccessI.write(b,0,nRead); JJE0q5[
//if(nThreadID == 1) Dq~D4|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u[1'Ap
} FLOSdMYdw
T~-PT39E
Z/=HQ8
Utility.log("Thread " + nThreadID + " is over!"); k[;(@e@c
bDownOver = true; Ih5F\eM
//nPos = fileAccessI.write (b,0,nRead); H%`|yUE(
} /mFa*~dj2
catch(Exception e){e.printStackTrace ();} mi$*,fz
} j{;IiVHnR
} /? HLEX
ryoD 1OE
e=EM07z
//打印回应的头信息 L9(!L$
public void logResponseHead(HttpURLConnection con) NW@guhK.
{ .eM A*C~n
for(int i=1;;i++) @P}!mdH1
{ s4Y7x.-
String header=con.getHeaderFieldKey(i); BJ7m3[lz
if(header!=null) &&{_T4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [[9XqD]
Utility.log(header+" : "+con.getHeaderField(header)); mRC6m K>
else nXcOFU
break; d"JI4)%
} P*sb@y>}O
} <bxp/#6D
+UC-
A]"IQ-
public void splitterStop() 1r;.r|
{ <MoKTP-<
bStop = true; U4$CkTe2Y
} t(?tPt4zp
9<S};I;
:p,DAt}
} Zp*0%x!e
K=X13As_
NKS-G2Y<P
/* ^J$?[@qD
**FileAccess.java q<*UeyE S
*//文件访问(定位，写) \hT=U*dMR
package NetFox; # ~T KC|G
import java.io.*; k->cqtG
60&4?<lR4
~J,e^$u
public class FileAccessI implements Serializable{ ^N_?&pgy
[EU\-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X7gtR|[
RandomAccessFile oSavedFile; J`x!c9zg7
long nPos; t|y`Bl2
YXWlg%s
J`4{O:{4
public FileAccessI() throws IOException KF4}cM=.5
{ V;-YM W
this("",0); m^Xq<`e"<
} ykbTWp$Y4Z
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"vG~2J
public FileAccessI(String sName,long nPos) throws IOException -THU5AB
{ C[h^bBq
oSavedFile = new RandomAccessFile(sName,"rw"); +HOHu*D
this.nPos = nPos; -%#F5br%
oSavedFile.seek(nPos); "G3zl{?GP
} 8o4?mhqV
S;FgS:;
8h| 9;%
public synchronized int write(byte[] b,int nStart,int nLen) O'} %Bjl
{ X0QLT:J b
int n = -1; %;{Ro)03
try{ A#P]|i
oSavedFile.write(b,nStart,nLen); oDEvhNT
n = nLen; YjM_8@<
} C%y!)v_x
catch(IOException e) QL4BD93v
{ Lw!Q*3c
e.printStackTrace (); 7-Yn8Gq
} RY]Vo8
;_vo2zl1
9:tn!<^=I
return n; #fR~7KR
} XY1eeB-
nm597WeZp
8hx 3pvmk
} Rg?m$$X`
[nnX,;
j[Xci<m
/* dW8M^A&
**SiteInfoBean.java PRE\2lLY
*/ :>'4@{'
package NetFox; {v>orP?
~HH6=qjU)
Q7-d]xJ^
public class SiteInfoBean { uNn]hl|x
.}.63T$h9
5,<:|/r
private String sSiteURL; //Site's URL ?Q XS?
private String sFilePath; //Saved File's Path ucVn `
private String sFileName; //Saved File's Name _(Qec?[^Ps
private int nSplitter; //Count of Splited Downloading File }.j09[<
RC| t-(Z
{tlt5p!4
public SiteInfoBean() <!r0[bKz@
{//nSplitter的缺省值为5 /Ky xOb)
//default value of nSplitter is 5 LT ZoO9O
this("","","",5); &CEZ+\bA
} "}jY;d#n
=(x W7Pt~
zsZP\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $stBB
{ hnbF}AD
sSiteURL= sURL; C/{tvY /o
sFilePath = sPath; k5%:L2FO
sFileName = sName; -:|1>og
this.nSplitter = nSpiltter; &b#O=LF
))qOsphN
C=z7Gk=
} X_0Ta_u?T
UmRI! WQl
U[Pll~m2b
public String getSSiteURL() `T]1u4^E
{ rfdT0xfcU
return sSiteURL; @}{~Ofs
} vQ/&iAyut
[aK7v{Wu
Ew|VDD(.
public void setSSiteURL(String value) _m+64qG_8'
{ BrQXSN$i
sSiteURL = value; (KF=v31_m
} ?u`TX_OsB
IC6}s
+4,v.B@
public String getSFilePath() b:,S
{ N<\U$\i
return sFilePath; ]ctlK'.
} *0 0K3
Yb<t~jm
I<'wZJRRa
public void setSFilePath(String value) Y GZX}-
{ FD&"k=p+X
sFilePath = value; Wy2 pa #Q
} S]7RGzFe
x[,HK{U|t
jJN.(
public String getSFileName() P1Z+XRWOM
{ Fj`6v"h
return sFileName; 7n1@m_7O
} )K4A-9pC
HW)4#nLhh
)4hb%U
public void setSFileName(String value) )@ /!B`
{ =3Y:DPMB
sFileName = value; yX:*TK4
} O+Zt*jN;
39w|2%(O.
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public int getNSplitter() _IA@X. )?
{ XL/?v" /
return nSplitter; ` R;6]/I?
} gsqpQq7
.."=
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public void setNSplitter(int nCount) _oB!-#
{ w+P?JR!)+
nSplitter = nCount; u'o."J^&'
} VFZ_Vw
} a]<y*N?qu
8u,f<XHi"a
@w)Vt$+b]
/* Xgge_`T9
**Utility.java H0zKL]D'>
*/ Fu*~{n
package NetFox; ?F@0"qi
hcvWf\4'#q
>i>%@
public class Utility { rpk )i:k\
?I6us X9$
nV|H5i;N7
public Utility() eB`7C"Z
{ K[%)_KW
,DN>aEu1
;TAf[[P
} HQ8oOn
nQ/R,+6h
//线程睡眠 fh0a "#L{
public static void sleep(int nSecond) -.8 nEO3
{ mCa[?
try{ }{J5)\s9
Thread.sleep(nSecond); l .8@F
} 6dG:3n}
catch(Exception e) ##gq{hgjb$
{ a&6e~E$K2
e.printStackTrace (); 9V]\,mD=
} y#'|=0vTvP
} V^a]@GK:
LV4]YC
//日志 }1ABrbc
public static void log(String sMsg) @S/jVXA
{ ;]* %wX
System.err.println(sMsg); H\OV7=8
} SH"e x,=
Iv6(Z>pAB
os<B}D[
public static void log(int sMsg) @z8,XW }
{ wHSas[4k
System.err.println(sMsg); l-Hp^|3Wq
} ggr\nY
} PVGvjc
pDGX$1O"
X>Cl{.
/* lg)jc3
**TestMethod.java 1gEeZ\B-&
*/ 1m*fkM#
package NetFox; 01n5]^.p
+Ar=89
"~y@rqIba
public class TestMethod { qNI2+<u)j
('qu#.'
(Kl96G<Wej
public TestMethod() <r_L-
{ ///xx/weblogic60b2_win.exe F;5S2:a@Z
try{ g$c\(isY;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1(z&0Y;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t(-`==.R
SiteFileFetch fileFetch = new SiteFileFetch(bean); J. ;9-
fileFetch.start(); :wn9bCom?M
} f%Y'7~9bA
catch(Exception e){e.printStackTrace ();} a?4'',~
Nwu,:}T
(^fiw%#
} C]ev"Am_)
W7k\j&x
1+1Z]!nG#!
public static void main(String[] args) _~?N3G
{ C NDf&dzX8
new TestMethod(); [89qg+z
} K3QE>@']
} 0Q^a*7w`8a
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