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)); qUxRM_7U
} |fSe>uVZ
for(int i=0;i<nEndPos.length-1;i++) U7I qST
{ Kt"BE j
nEndPos = nStartPos[i+1]; k'#(1(xj
} Nkp)Ax&
nEndPos[nEndPos.length-1] = nFileLength; 6S+U&Ce\
} " t7M3i_
} LxpuhvIO
xA9:*>+>
VY)9|JJCO
//启动子线程 z}{afEb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #{=;NuP
for(int i=0;i<nStartPos.length;i++) 5g9; +}X;
{ DSt]{fl`P
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nzmDA6d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !OT-b>*w
nStartPos,nEndPos,i); :dLAs@z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cIp D~0\
fileSplitterFetch.start(); /r-aPJX
} * 1Od-3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uPRQU+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ay !G1;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @DZB9DDR
nEndPos = " + nFileLength); CT1ja.\;
// fileSplitterFetch[nPos.length-1].start(); 2AtLyN'.
(ZY@$''
V^\8BVw
//等待子线程结束 j%y$_9a7
//int count = 0; 6$ Gep
//是否结束while循环 }J7zTj~{
boolean breakWhile = false; <x&%~6j
Tp0bS
.N*Pl(<[
while(!bStop) VMCLHpSfW
{ Gkp<o
write_nPos(); $2u 'N:o
Utility.sleep(500); WdnIp!
breakWhile = true; :"l-KQ0
%zSuK8kxV
fwBRWr9
for(int i=0;i<nStartPos.length;i++) .VkbYK
{ Dgx8\~(E'
if(!fileSplitterFetch.bDownOver) J]q%gcM
{ 1*dRK6
breakWhile = false; 7{xh8#m
break; k<cgO[m
} l2&`J_"
} #hlCs
if(breakWhile) ^k Cn*&
break; |QMhMGjV
V=lfl1Ev0J
*bxzCI7b
//count++; l983vKr
//if(count>4) %/>Y/!;
// siteStop(); IXb}AxBf
} =&},;VOh
}=|!:kiE
qY>{cjo
System.err.println("文件下载结束！"); ?_v{| YI=
} EZYBeqv
catch(Exception e){e.printStackTrace ();} 8o/}}=m$
} 5r?m&28X
NuYkz"O]
]XTu+T.aT
//获得文件长度 Z(9u<
public long getFileSize() 8HZs>l
{ lhi_6&&[8
int nFileLength = -1; ;r6jx"i
try{ tw(JZDc
URL url = new URL(siteInfoBean.getSSiteURL()); 9{$'S4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HFqm6|
httpConnection.setRequestProperty("User-Agent","NetFox"); 4<x'ocKlD
/'hCi]b@v
W,K%c=
int responseCode=httpConnection.getResponseCode(); (?H0+zws^
if(responseCode>=400) & u!\<\
{ YOrrkbJ(
processErrorCode(responseCode); NBF MN%
return -2; //-2 represent access is error de]zT^&C
} ,&d@O>$E:
t!2(7=P30(
Vf`7V$sr
String sHeader; Iu{kPyx
XTd3|Pm
I"1;|`L~:
for(int i=1;;i++) c5Q<$86
{ &|aqP \Q5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); i[ $0a4
//Utility.log(in.readLine()); >5wx+n)/)
sHeader=httpConnection.getHeaderFieldKey(i); DaH?@Q
if(sHeader!=null) gZEi]/8_
{ 5"/J^"!h
if(sHeader.equals("Content-Length")) Lgz$]Jbl8
{ 2jbIW*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $46{<4.
break; -!)xQvagD.
} !I\!;b
} &h~Xq^
else k6kM'e3V
break; \3Q&~j
} h!#:$|Q
} Sggq3l$Qc
catch(IOException e){e.printStackTrace ();} 0oh]61gC
catch(Exception e){e.printStackTrace ();} E0/mSm"(T
Z--@.IYoJ
#UtFD^h
Utility.log(nFileLength); `y+-H|%?
WO6/X/#8b
$HG}[XD?
return nFileLength; fA=#Fzk2
} n$aA)"A #
'&99?s`u
xcJ`1*1N
//保存下载信息（文件指针位置） 5*\\J&H
private void write_nPos() kSc{^-<R
{ ^ZM0c>ev=l
try{ 2S8P}$mM
output = new DataOutputStream(new FileOutputStream(tmpFile)); P"lBB8\eku
output.writeInt(nStartPos.length); ;Efcw[<
for(int i=0;i<nStartPos.length;i++) F3oQ^;xB
{ +f0~D(d!_
// output.writeLong(nPos); hfcIvs/!
output.writeLong(fileSplitterFetch.nStartPos); lc6iKFyG
output.writeLong(fileSplitterFetch.nEndPos); -B$~`2-
} u4"SH(
output.close(); E`j-6:
} i-U4RZE
catch(IOException e){e.printStackTrace ();} za'6Y*CGgX
catch(Exception e){e.printStackTrace ();} 1 ^g t1o
} |+U<S~
f(D_FTTO
]MtFf6&
//读取保存的下载信息（文件指针位置） gq"k<C0
private void read_nPos() iU+nqY'
{ h7X_S4p/Mg
try{ 1ZJQs6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N4K8 u'f^
int nCount = input.readInt(); XCsiEKZ_i
nStartPos = new long[nCount]; ^Cv^yTj;&
nEndPos = new long[nCount]; ]l~V&#i_c
for(int i=0;i<nStartPos.length;i++) O8U<{jgAG
{ !TAp+b
nStartPos = input.readLong(); as+GbstN
nEndPos = input.readLong(); $3X-rjQtW
} /Jf~25F
input.close(); ,&HR(jTo
} OOBhbpg!D
catch(IOException e){e.printStackTrace ();} Zc"B0_&?:7
catch(Exception e){e.printStackTrace ();} >%Ee#m
} >\<*4J$PZ
}]UB;id'
L?Yoh<
private void processErrorCode(int nErrorCode) N:VX!w
{ W YW|P2*
System.err.println("Error Code : " + nErrorCode); o$.e^XL
} r,(et
nsb4S{
~e@>zoM'^
//停止文件下载 @OV-KT[>
public void siteStop() zVv04_:
{ jy2IZ o
bStop = true; .7ayQp
for(int i=0;i<nStartPos.length;i++) Fk=}iB#(
fileSplitterFetch.splitterStop(); Hqz?E@bc@
Wk4.%tpeO7
rC[6lIP
} B6}FIg)
} Dbx~n#nG
//负责部分文件的抓取 $!A:5jech
**FileSplitterFetch.java f]8I64
*/ ]J2:194
package NetFox; rAdacnZV
Gi^Ha=?J%
.wrL3z_
import java.io.*; n uQM^2
import java.net.*; :Zw@yt
!SHj$Jwa'
7@%'wy&A
public class FileSplitterFetch extends Thread { _L.n,
% 0:p)Z0
vOI[Z0Lq9h
String sURL; //File URL -m 5}#P89
long nStartPos; //File Snippet Start Position *B)yy[8j+
long nEndPos; //File Snippet End Position io4A>>W==/
int nThreadID; //Thread's ID tZWrz e^
boolean bDownOver = false; //Downing is over M] V.!z9B
boolean bStop = false; //Stop identical IxDWJ#k
FileAccessI fileAccessI = null; //File Access interface zGcqzYbuA
]"fsW 9s
&B{8uge1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |-2}j2'
{ IF k
this.sURL = sURL; t@bt6J .{
this.nStartPos = nStart; `BZ&~vJ_
this.nEndPos = nEnd; |I[7,`C~
nThreadID = id; '3l$al:H^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3mt%!}S
} 6\dX
Md;/nJO~{
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public void run() ZX`J8lZP
{ M"^K0 .
while(nStartPos < nEndPos && !bStop) u>T76,8|\
{ QYE7p\
WNa0,
U Lmg$T&
try{ U!q[e`B
URL url = new URL(sURL); NSLVD[yT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iT)WR90
httpConnection.setRequestProperty("User-Agent","NetFox"); q(z7~:+qNr
String sProperty = "bytes="+nStartPos+"-"; eTE2J~\
httpConnection.setRequestProperty("RANGE",sProperty); Z&yaSB
Utility.log(sProperty); ,WTTJN
2C+(":=}
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InputStream input = httpConnection.getInputStream(); T>]sQPg
//logResponseHead(httpConnection); t)1phg4H)
nZvU'k:
f_r0})
byte[] b = new byte[1024]; u"VS* hSH
int nRead; K!8zwb=fq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?p8Qx\%*
{ Ns~&sE:
nStartPos += fileAccessI.write(b,0,nRead); 1IA5.@G:
//if(nThreadID == 1) &,W$-[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KHj6Tg;)
} 6!7Pm>ml
+$beo2x6
[F([
Utility.log("Thread " + nThreadID + " is over!"); ^o<[. )
bDownOver = true; s^|\9%WD
//nPos = fileAccessI.write (b,0,nRead); 99ASIC!
} w^VSj%XH!
catch(Exception e){e.printStackTrace ();} whkJpK(
} L=1~ f-
} 0'ZYO.y
mc@M,2@D
{K.rl%_|N
//打印回应的头信息 {gkwOMW
public void logResponseHead(HttpURLConnection con) 2)LX^?7R
{ /(6zsq'v|
for(int i=1;;i++) }ymvC
{ nmE5]Pcg
String header=con.getHeaderFieldKey(i); 0^<,(]!
if(header!=null) ,w\ wQn>]K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %O) Z
Utility.log(header+" : "+con.getHeaderField(header)); af>3V(7
else #vnT&FN0[
break; {OxWcK\2@h
} ^e9aD9
} :0Te4UE;P7
Ee?;i<u
(:}<xxl
public void splitterStop() zHFTCL>"
{ Wvr+y!F
bStop = true; $pu3Ig$^
} 4]BJ0+|mT
nP_=GI
x0x $ 9
} kEAhTh&g*
zA{8C];~
3q~Fl=|.o
/* @InJ_9E
**FileAccess.java KS! iL=i
*//文件访问(定位，写) (|0b7|'T
package NetFox; r@$B'CsLj
import java.io.*; 6&],WGz
46ChMTt
.~<]HAwq
public class FileAccessI implements Serializable{ )fCMITq.|
f'_S1\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \!PV*%P
RandomAccessFile oSavedFile; Jr?!Mh-
long nPos; t,Q'S`eTU
V4?Oc2mS
hZF(/4Z2
public FileAccessI() throws IOException ,kE=TR.|
{ Tf l;7w.(A
this("",0); 7|~:P$M
} 3/tJDb5
q!2<=:f
;Uk!jQh
public FileAccessI(String sName,long nPos) throws IOException u%aFb*
{ M71R -B`-
oSavedFile = new RandomAccessFile(sName,"rw"); (HSw%e
this.nPos = nPos; $[QcEk
oSavedFile.seek(nPos); @U7Dunu*f
} 51/sTx<Z}
Vj7Hgc-,
nt`<y0ta
public synchronized int write(byte[] b,int nStart,int nLen) |8;? *s`H
{ i@{*O@m
int n = -1; 8_awMVAy
try{ ~h|m&XK+Q
oSavedFile.write(b,nStart,nLen); |$Xf;N37t
n = nLen; XW:%vJu^`
} &fHc"-U}
catch(IOException e) \)GR\~z0h
{ @YNGxg~*g
e.printStackTrace (); #fzw WP
} 7<4xtK`+b
[iXi\Ex
/fC\K_<N
return n; MBv/
} LH.%\TMN$
4]u,x`6C
w=$'Lt!
} JP_kQ
q-uLA&4
#-dK0<:
/* NCxn^$/+>9
**SiteInfoBean.java 500> CBL0O
*/ @:IL/o*
package NetFox; |Ib.)
Y`=z.D{
1!s!wQgS
public class SiteInfoBean { &$Ci}{{n#
-PXoMZx%
7A[Ogro
private String sSiteURL; //Site's URL jRwa0Px(
private String sFilePath; //Saved File's Path Wa{%0inZ
private String sFileName; //Saved File's Name hJ4S3b
private int nSplitter; //Count of Splited Downloading File r?]%d!
#O><A&FrF`
s%bUgO%&
public SiteInfoBean() ~RCg.&[ou
{//nSplitter的缺省值为5 M0L-u
//default value of nSplitter is 5 7>KQRLw
this("","","",5); `M6YblnJZ
} k)Zn>
2gH_$
AW62~*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mMslWe
{ fxOE]d8v
sSiteURL= sURL; lnjL7x
sFilePath = sPath; `L;OY 4
sFileName = sName; Bjtj{B
this.nSplitter = nSpiltter; CJ:uYXJJ:z
/xF 9:r
6VGo>b;
} fvO;lA>`
BZ}`4W'
z=[l.Af_
public String getSSiteURL() Slo9#26
{ |C|:i@c H
return sSiteURL; a/QIJ*0
} `{%-*f^
h2AGEg'g2[
V3 qT<}y|
public void setSSiteURL(String value) >Rr!rtc'x
{ *qbRP"#[$
sSiteURL = value; ^b:Xo"q#H
} y3Y2QC(
)'=V!H#U*
_J` |<}?t;
public String getSFilePath() > Z]P]e
{ #*+;B93)
return sFilePath; gfxoJihE
} ]u~Os<
l,^xX=,
pAMo XJ`
public void setSFilePath(String value) >2nF"?"=
{ 7Onk!NH
sFilePath = value; 3V"dG1?
} q$3HvZP
kGruo5A
CJ0$;et
public String getSFileName() nhp)yW
{ x Ridc^
return sFileName; %;'~%\|dZM
} B%)zGTp6
QZ#3Bn%B5
:l4^iSf
public void setSFileName(String value) ysL0hwir
{ j-j'phK
sFileName = value; RFhU#
} gYRqqV
MPqY?KF
m9%yR"g9
public int getNSplitter() {`tHJ|8
{ 4$..r4@
return nSplitter; w4NZt|>5j;
} |&9tU
l.sm~/
]~$c~*0g
public void setNSplitter(int nCount) gv`%Z8u(
{ ]aREQ?ma&z
nSplitter = nCount; *X%?3"WH8
} sV]i/B
} @wg&6uQ
/DK*yS
zUe#Wp[
/* rve7YS'
**Utility.java jM{qRfOrg
*/ \MfR #k0
package NetFox; |:~("rA+v
*QMF <ze
Ma% E&.ed
public class Utility { 22l|!B%o
2=i+L z^
jn0t-":
public Utility() u!hqq^1
{ Bidqf7v
6(\q< fx
q]2}UuM|U
} "K9vm^xP
UDhwnGTq(l
//线程睡眠 _HSTiJVr
public static void sleep(int nSecond) 8h55$j
{ y.L|rRe@P
try{ Wh#os,U$
Thread.sleep(nSecond); jI@bTS o
} U/}AiCdj@
catch(Exception e) Pc/.*kOT
{ cP/F|uG5
e.printStackTrace (); MBnK&GS
} .%-6&%1
} Tb>IHoil
8:;u v7p
//日志 k#{lt-a/
public static void log(String sMsg) 3(oZZz
{ I8E\'`:<
System.err.println(sMsg); f'7d4
} .Y=Z!Q
K8e4ax
]L5Z=.z&
public static void log(int sMsg) SQz$kIZR
{ g?k#wj1uH
System.err.println(sMsg); yt]Oj*nn0K
} Fm-q=3
} &!3VqHQ`
`kaR@t
a!s.850@
/* ymzPJ??!
**TestMethod.java <z~2d
*/ HYa$EE2
package NetFox; hlABu)B'1
_47j9m]f
r"HbrQn
public class TestMethod { X^?|Sz<^E
7]<F>97
vV$hGS(f~
public TestMethod() p*(U*8Q
{ ///xx/weblogic60b2_win.exe M ,.0[+
try{ )'/nS$\E:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); j\jL[hG_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x mrugNRg
SiteFileFetch fileFetch = new SiteFileFetch(bean); WrIL]kJw^
fileFetch.start(); 6Zl.Lh
} 8AC.2v?_
catch(Exception e){e.printStackTrace ();} %_%f#S
KoxGxHz^Y3
{="Su{i}}
} ebl)6C
q.u[g0h;
YU ]G5\UU
public static void main(String[] args) UIm[DYMS
{ (}/.4xE
new TestMethod(); R-2FNl
} ,YAPCj
} d~P<M3#>
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