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)); L6Ykv/V
} HDZB)'I
for(int i=0;i<nEndPos.length-1;i++) abkl)X>k
{ V #W,}+_Sz
nEndPos = nStartPos[i+1]; _eM\ /(v[
} z9pv|
nEndPos[nEndPos.length-1] = nFileLength; blNJ
} u HqPb8
} TaeN?jc5
"Q6oPDX(
"S.5_@?
//启动子线程 | ?3\xw
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $^?"/;8P5
for(int i=0;i<nStartPos.length;i++) ciVN-;vi
{ 5mUHk]W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f4)fa yAVp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v{ Md4p
nStartPos,nEndPos,i); Tz3 L#0:j
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9 o6ig>C
fileSplitterFetch.start(); w~hO)1c],:
} B}8xA}<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &{NN!X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g-"@%ps
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `z%f@/:fG
nEndPos = " + nFileLength); 4Tgy2[D?q
// fileSplitterFetch[nPos.length-1].start(); St9W{
Y%y=
=#dW^?p
//等待子线程结束 o<bZ.t
//int count = 0; /"?yB$s
//是否结束while循环 E}Q'Wz|k
boolean breakWhile = false; Z .VIb|
p/L|;c
hRTw8-wy:
while(!bStop) 9HrT>{@
{ L,c@Z@
write_nPos(); r18euB%
Utility.sleep(500); reJw&t}Q
breakWhile = true; Z8*E-y0
lJ;7sgQ#
ste0:.*qb
for(int i=0;i<nStartPos.length;i++) Jt5\
{ ;+] mcgN!
if(!fileSplitterFetch.bDownOver) (CFm6p'RZ
{ O_}R~p
breakWhile = false; NovF?kh2
break; "/[xak!g
} N|-M|1w96
} n4,b?-E>(
if(breakWhile) Uo?g@D
break; !qk+>6~A,
I WKq_Zjkz
F,+nj?i!
//count++; qww*
//if(count>4) %0l'Nuz
// siteStop(); S?ELFq(g
} a)w *
)(yD"]co
zLEl/yPE
System.err.println("文件下载结束！"); =p~k5k4
} tb36c<U-
catch(Exception e){e.printStackTrace ();} \6AYx[|
} TLbnG$VQS
o;5 J=
ScOiOz:Ha
//获得文件长度 v,bCj6
public long getFileSize() K",YAfJa
{ &iR3]FNI
int nFileLength = -1; :}(Aq;}X
try{ dC+WII`V
URL url = new URL(siteInfoBean.getSSiteURL()); 8h"Val|qP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zA/tHlKc
httpConnection.setRequestProperty("User-Agent","NetFox"); &zkuL
Kv(2x3("
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int responseCode=httpConnection.getResponseCode(); VRden>vKN
if(responseCode>=400) CqK&J /8
{ mY6d+
processErrorCode(responseCode); 0?c2=Y
return -2; //-2 represent access is error cW%QKdTQY0
} ! Rrk
\cJ?2^Eq
Sd[%$)scC
String sHeader; +I~`Ob
[ye!3h&]
b)ytm=7ha
for(int i=1;;i++) ^#-d^ )f;
{ 4z6i{n-k
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _v=S4A#tF
//Utility.log(in.readLine()); k*XI/k5Vc
sHeader=httpConnection.getHeaderFieldKey(i); 9~3;upWu!
if(sHeader!=null) v *'anw&Z
{ 4-j3&(
if(sHeader.equals("Content-Length")) 24{Tl q3
{ T($d3Nn1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uBpnfIe
break; V9KI?}q:W
} 5PF?Eq
} K|^PHe
else 80J87\)
break; S7oPdzcU-
} }-`N^
} %vF,wQC
catch(IOException e){e.printStackTrace ();} ?XCFRt,ol
catch(Exception e){e.printStackTrace ();} \e)>]C}h
@nWhUH%
/Z3 Mlm{
Utility.log(nFileLength); |!t&ZpdD
9t$#!2z
*Wbs{>&No
return nFileLength; hSAdD!
} oVZI([O
srS2v\1:
rF@njw@
//保存下载信息（文件指针位置） 6ijL+5
private void write_nPos() 1`6kc9f.
{ sF.oZ>
try{ _\"2Mdk`]
output = new DataOutputStream(new FileOutputStream(tmpFile)); _PPZ!r(
output.writeInt(nStartPos.length); QK~44;LVIJ
for(int i=0;i<nStartPos.length;i++) FS'|e?WU
{ )NF5,eD
// output.writeLong(nPos); b@v_db]|t.
output.writeLong(fileSplitterFetch.nStartPos); q8Jhs7fv
output.writeLong(fileSplitterFetch.nEndPos); E5;6ks)
} bF2RP8?en
output.close(); 1s-dqHz"s
} ~Un+Zs%24
catch(IOException e){e.printStackTrace ();} pVm]<jO
catch(Exception e){e.printStackTrace ();} q\DN8IJ
} IL0e:-@!0
hw5NHZ I'
Fal##6B
//读取保存的下载信息（文件指针位置） EKgY
private void read_nPos() lIhP\:;S&
{ g49G7sk
try{ !l6Ez_'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W(4Mvd
int nCount = input.readInt(); $Wy(Wtrx|
nStartPos = new long[nCount]; %3%bRP
nEndPos = new long[nCount]; 1 b&<De
for(int i=0;i<nStartPos.length;i++) yf4I<v$y
{ 9ZJn 8ki
nStartPos = input.readLong(); +x!Hc
nEndPos = input.readLong(); %[cZ,F=
} C(%b!Q,2
input.close(); H^3f!\MC;o
} 60\`TsFobT
catch(IOException e){e.printStackTrace ();} PEr &|H2
catch(Exception e){e.printStackTrace ();} Tv[|^G9x
} Tv[h2_+E
|l-~,eRvi5
8(zE^W,[8"
private void processErrorCode(int nErrorCode) J#'8]p3E
{ }AW"2<@
System.err.println("Error Code : " + nErrorCode); Y+d+
} mAM:Q*a'
W(jOD,QMB
ikd1KF+I
//停止文件下载 1agNwFd~
public void siteStop() )5[OG7/g
{ c80Ffq
bStop = true; mOC<a7#
for(int i=0;i<nStartPos.length;i++) (-D^_*f
fileSplitterFetch.splitterStop(); p3,m),
[%c5MQ?H
JW},7Ox
} ?S<`*O +
} `VrQ?s
//负责部分文件的抓取 O7"16~a
**FileSplitterFetch.java ~dBx<
*/ wi/qI(O!
package NetFox; d=nv61]
9oU1IT9
,+4*\yI3l
import java.io.*; x%'5rnm|
import java.net.*; Q2>o+G
C+L_f_6]
*t{^P*pc
public class FileSplitterFetch extends Thread { ^`S.Mw.
f6,?Yex8B
}`pxs
String sURL; //File URL oh0*bh
long nStartPos; //File Snippet Start Position ^O3i)GO
long nEndPos; //File Snippet End Position p:NIRs
int nThreadID; //Thread's ID 3iIURSG@
boolean bDownOver = false; //Downing is over ,<(0T$o E[
boolean bStop = false; //Stop identical ?CD[jX}!
FileAccessI fileAccessI = null; //File Access interface e?7Oom
4%$#
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )Drif\FF)
{ +;ylld
this.sURL = sURL; #|"M
this.nStartPos = nStart; (zX75QSKV
this.nEndPos = nEnd; t-i\gq^
nThreadID = id; (PC)R9r5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2EH0d6nt
} fm0]nT
#F=!g?
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public void run() yBRYEqS+
{ Js<DVe,
while(nStartPos < nEndPos && !bStop) /,,IM/(6^
{ `$9sYv 2R
O)!S[5YI
nN2huNTf:
try{ {O6yJckH
URL url = new URL(sURL); z5J$".O`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (nwp s
httpConnection.setRequestProperty("User-Agent","NetFox"); @R_ON"h
String sProperty = "bytes="+nStartPos+"-"; g/4ipcG;N
httpConnection.setRequestProperty("RANGE",sProperty); X7rsO^}W
Utility.log(sProperty); J(:y-U
90 >V he
7NRm\%^q
InputStream input = httpConnection.getInputStream(); g3 opN>W
//logResponseHead(httpConnection); xpp>5d !
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byte[] b = new byte[1024]; aHdQi,=z
int nRead; [pC2#_}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W2&(:C8V@
{ aL&nD1f=!-
nStartPos += fileAccessI.write(b,0,nRead); ,1B`Ve
//if(nThreadID == 1) ?IG[W+M8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8},:
} t,u;"%go
Kk).KgR
"QvTn=
Utility.log("Thread " + nThreadID + " is over!"); N F,<^ u
bDownOver = true; _fccZf(yC.
//nPos = fileAccessI.write (b,0,nRead); @R Jr ~y0
} [:zP]l.|
catch(Exception e){e.printStackTrace ();} ^'n;W<\p)
} c,:nWf
} p^1~o/
S%jW}v';
X"sJiFS
//打印回应的头信息 H*P[tyz$
public void logResponseHead(HttpURLConnection con) L_tjclk0J
{ @)C.IQ~
for(int i=1;;i++) `pjB^--w
{ p<<dj%
String header=con.getHeaderFieldKey(i); #;=sJ[m4
if(header!=null) [tRb{JsUd
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PQ{5*}$N
Utility.log(header+" : "+con.getHeaderField(header)); Ciy%7_~\
else q+} \(|
break; =!G{+&j
} \mL]xE-
} <Uc
?./%7v
|\>Ifv%{
public void splitterStop() 1ASoH,D/
{ $AizKiV
bStop = true; xf{ZwS%X
} CEVisKcE:
-Jf}3$Ra
1aZGt2;
} D"2bgw
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((&5F!+\-
/* CDPu(,^
**FileAccess.java G+2 ,x0(
*//文件访问(定位，写) hV+=hX<h
package NetFox; M?AKJE j5
import java.io.*; kS?CKd9by
^wD`sj<Qg
Omi/sKFMi
public class FileAccessI implements Serializable{ 0cDP:EzR;
Y^nm{;G+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /=T:W*C
RandomAccessFile oSavedFile; 7xFZJ#
long nPos; lwz\"8
a;v4R[lQ
F+ 7*SImv6
public FileAccessI() throws IOException $fBj}\o
{ h?H|)a<^9
this("",0); $wn0oIuW
} [k0/ZfFwV
vvu $8n
M ziOpraj
public FileAccessI(String sName,long nPos) throws IOException Wffz&pR8
{ &E1m{gB(
oSavedFile = new RandomAccessFile(sName,"rw"); Y;'SD{On
this.nPos = nPos; $}'(%\7"
oSavedFile.seek(nPos); Zu<S<??Jf
} -w>ss&
5fMlOP_
Pf/8tXs}
public synchronized int write(byte[] b,int nStart,int nLen) 0yvp>{;p
{ :wN!E{0j
int n = -1; 1+Uem
try{ 1J72*`4OK
oSavedFile.write(b,nStart,nLen); S;y4Z:!
n = nLen; E[6:}z<
} T"aE]4_
catch(IOException e) 3Fxr=
{ E NCWOj
e.printStackTrace (); \*Yr&Lm
} bdLi_k
L`e19I$
:5.F
return n; V#5$J Xp
} /[D_9
U82mO+}
J3(E{w8Q
} 4 R(m$!E!
HTv#2WX
QxN1N^a0
/* qE|syA9
**SiteInfoBean.java .ANR|G
*/ hSR+7qN<e
package NetFox; 2P)O 0j\/
`uUzBV.FR
kN78j
public class SiteInfoBean { I{r*Y9
l^OflZC~
ZHa>8x;Mjl
private String sSiteURL; //Site's URL Yb4ku7}
private String sFilePath; //Saved File's Path kY!zBk
private String sFileName; //Saved File's Name !_QT{H
private int nSplitter; //Count of Splited Downloading File 77y+ik
E1tCY.N{
dq`{fqGl
public SiteInfoBean() 8e3eQ
{//nSplitter的缺省值为5 K!.t}s.t
//default value of nSplitter is 5 E>f{j:M
this("","","",5); l)dE7$H
} $B_%MfI
gua7<z6=eh
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {wsJ1v8!
{ =*jFaj
sSiteURL= sURL; ""XAUxo
sFilePath = sPath; *U]&a^N
sFileName = sName; xY#J((-iH
this.nSplitter = nSpiltter; J{-`&I'b
11YJW-V
S2;^
} VgODv
1:<(Q2X%
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public String getSSiteURL() } `r.fD
{ U1X"UN)
return sSiteURL; 86N,04
} -{k8^o7$
83SK<V6
IQ~qiFCf
public void setSSiteURL(String value) 9#@s(s
{ Ie!&FQe2q
sSiteURL = value; `=P_ed%&'
} Mmu#hb|W
H$C*&p
BZHoRd{EH
public String getSFilePath() ]W14'Z
{ Xd5s8C/}
return sFilePath; o2U5irU
} t@9-LYbL
V){Io_"
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public void setSFilePath(String value) u*;H$&
{ Wm`*IBWA
sFilePath = value; p\&/m
} R"V90bCf
*bf 5A9
<{Y3}Q
public String getSFileName() ~{tO8 ]
{ |xcC'1WU
return sFileName; sdg2^]|
} #gO[di0WhC
c/A?-9
+cqUp6x.
public void setSFileName(String value) q,@# cQBV
{ h!%y,4IBR
sFileName = value; 1xd6p
} 6bhb_U'f
< $e#o H
CYgokS\=,
public int getNSplitter() ZxSFElDD]E
{ <tFq^qB
return nSplitter; (,#m+
} (k #xF"yI
#f24a?n|
k}H7bZug
public void setNSplitter(int nCount) aH?Ygzw
{ <_<zrXc]
nSplitter = nCount; X+N5iT
} GZu12\0nZ
} |<h}'
*)-@'{]uB
Ovk=s,a)K
/* BLt58LYGX
**Utility.java O}Pqbx&
*/ $Y_S`#c@i
package NetFox; M.t,o\xl
U|tacO5w`
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public class Utility { vLHn4>J,R
6[k<&;
TS9<uRO0
public Utility() (LmU\Pe%
{ cYK:Y!|`F
F&R*njJcc
M-i3_H)
} 9X4[Zk
@ewaj!
//线程睡眠 iSezrN
public static void sleep(int nSecond) d;YKw1
{ Slg*[r#
try{ n({%|O<|
Thread.sleep(nSecond); b.RU%Y#>\
} /Tm+&Jd
catch(Exception e) L7buY(F(
{ 6CHb\k
e.printStackTrace (); 0H>gMXWE]
} zu{K"7Bx
} p4f9v:b[
7Qd$@ m
//日志 xH:L6K/c
public static void log(String sMsg) j}//e%$a
{ ~9FL]qo
System.err.println(sMsg); A)"L+Yu5
} Dh2Cj-| ~
U52V1b
z~vcwiYAP
public static void log(int sMsg) GWuKDq
{ G)I` M4}*n
System.err.println(sMsg); }6-olVg
} y4h =e~
} $rcv@-l
;K\2/"$QD
}WIkNG4{Z
/* E,.PT^au
**TestMethod.java uM1$3<
*/ #W)m({}
package NetFox; ?g4Rk9<!i
V/2NIh
'[liZCg
public class TestMethod { uPl}NEwU|
f^1J_}cL
&Ril[siw
public TestMethod() bl a`B=r
{ ///xx/weblogic60b2_win.exe w6!97x
try{ AH&RabH2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uthW AT &
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |;~=^a3?q
SiteFileFetch fileFetch = new SiteFileFetch(bean); qA!p7"m|
fileFetch.start(); OJa(Gds
} 4RVqfD
catch(Exception e){e.printStackTrace ();} jdJTOT
@ !su7
k*N!U[]
} Vq]ixag2^
i;9X_?QF
v; i4ZSV^A
public static void main(String[] args) lM4Z7mT /
{ )1#/@cU
new TestMethod(); Xrb7.Y0d
} ?{"r(
} VBi gUK4
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