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)); );nz4/V
} "K,bH
for(int i=0;i<nEndPos.length-1;i++) UP\C"\
{ YMT8p\#rp
nEndPos = nStartPos[i+1]; "OO96F
} U^[<
nEndPos[nEndPos.length-1] = nFileLength; %JQ~!3
} 6O9iEc,HM
} czI{qi5N
mj@31YW
n@ 4@,
//启动子线程 4r\*@rq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tQrS3Hz'nA
for(int i=0;i<nStartPos.length;i++) .`,F
{ /|GT\X4o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KbAR_T1n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &y70
nStartPos,nEndPos,i); L\YKdUL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G$C}?"l
fileSplitterFetch.start(); ;7rd;zJ
} 5SUN.%y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r} Lb3`'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Edw2W8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", QBoFpxh=
nEndPos = " + nFileLength); -/>9c-F
// fileSplitterFetch[nPos.length-1].start(); "V4Q2T T
T7{<arL$
cGNvEM(4AV
//等待子线程结束 7:>sc]Z
//int count = 0; gE\b982
//是否结束while循环 I5qM.@%zB
boolean breakWhile = false; 86%%n?"}
~wOTjz
["a"x>X&
while(!bStop) ?6f7ld5
{ 9@ndiu[
write_nPos(); |jT2W
Utility.sleep(500); x? N.WABr;
breakWhile = true; C/G]v*MBQ
"(,2L,Zh
f2yq8/J8.
for(int i=0;i<nStartPos.length;i++) N5?IpE
{ llq*T"7
if(!fileSplitterFetch.bDownOver) gWOt]D&#/
{ #{$1z;i?f
breakWhile = false; T~Ly^|Ihz
break; wiJRCH
} 56DoO'
} qbiK^gR
if(breakWhile) X4wH/q^
break; ZQAO"huk]
,[isib3
@'i+ff\
//count++; ;F5"}x
//if(count>4) <~{du ?4n
// siteStop(); *%\mZ,s"
} :"QfF@Z{
NQX>Qh 2
o0ZBi|U\4
System.err.println("文件下载结束！"); vvq/
} sb^mLH] 3
catch(Exception e){e.printStackTrace ();} l!?yu]Yon
} F2;:vTA>
OQp, 3M{_
|0sPka/u16
//获得文件长度 #G#g|x*V
public long getFileSize() R,t$"bOd
{ S2K#[mDG
int nFileLength = -1; %2"J:0j
try{ E!J=8C.:
URL url = new URL(siteInfoBean.getSSiteURL()); PLA#!$c7q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _c2WqQ-05
httpConnection.setRequestProperty("User-Agent","NetFox"); `G!M>h@
~y /!fnv
A]o4Mf0>I
int responseCode=httpConnection.getResponseCode(); hJ*Ihwn|
if(responseCode>=400) B=n[)"5fBO
{ SV.z>p
processErrorCode(responseCode); 5u$D/* Eb
return -2; //-2 represent access is error &!L:"]=+
} =']3(6*
V`#.7uUP
C\}/"
String sHeader; 8 #}D :(
tfYB_N
|3shc,7
for(int i=1;;i++) bgF^(T35
{ BRS#Fl:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'yY>as
//Utility.log(in.readLine()); lCIDBBjy^
sHeader=httpConnection.getHeaderFieldKey(i); XNehPZYS
if(sHeader!=null) GZ3 ]N
{ }Fa%%}
if(sHeader.equals("Content-Length")) J?&l*_m;t
{ +=BAslk
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;65D
break; y(W|eBe
} KxzYfH
} `~#<&w
else =0qpVFvU
break; {"S6\%=
} D`yEwpV^
} J2VTo: In
catch(IOException e){e.printStackTrace ();} mr:CuqJ
catch(Exception e){e.printStackTrace ();} W*N$'%
IH9.F
By)u-)g9
Utility.log(nFileLength); y<:<$22O
5/MKzoB
^D{lPu 3
return nFileLength; -/P\"c
} .}B(&*9,v
X4|4QgY
\%0n}.A
//保存下载信息（文件指针位置） r'GP$0rr9!
private void write_nPos() j%IF2p2
{ Oy57$
try{ Yg9joNBh
output = new DataOutputStream(new FileOutputStream(tmpFile)); @FO)0
output.writeInt(nStartPos.length); *L4`$@l8
for(int i=0;i<nStartPos.length;i++) Lel|,mc`k2
{ QDx$==Fo
// output.writeLong(nPos); )e|=mtp
output.writeLong(fileSplitterFetch.nStartPos); uXjP`/R|
output.writeLong(fileSplitterFetch.nEndPos); em{(4!W>
} P{Lf5V9# <
output.close(); oczG|_
} !C4!LZ0A
catch(IOException e){e.printStackTrace ();} "N?+VkZEv
catch(Exception e){e.printStackTrace ();} u #w29Pm
} oU*45B`"
G\de2Q"d:O
v'!a\b`9
//读取保存的下载信息（文件指针位置） ^T::-pN*
private void read_nPos() iBTYY{-wF
{ "A$!, PX6
try{ t. ='/`!N
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); **3 z;58i
int nCount = input.readInt(); 9iUrnG*
nStartPos = new long[nCount]; vw,rF`LjZ
nEndPos = new long[nCount]; "VG+1r+]4
for(int i=0;i<nStartPos.length;i++) %Dg0fL
{ ^(HUGl_
nStartPos = input.readLong(); }7E^ZZ]f
nEndPos = input.readLong(); ~*A8+@\R
} 4)|8Eu[p7
input.close(); kE9esC3
} !K f#@0E..
catch(IOException e){e.printStackTrace ();} aFz5leD
catch(Exception e){e.printStackTrace ();} Gs+3e8
} Eow_&#WW;P
a2'^8;U*_
L|P5=/d
private void processErrorCode(int nErrorCode) d?`ny#,GB
{ aE;le{|!({
System.err.println("Error Code : " + nErrorCode); eq(am%3~
} 0j"8@<
}X*Riu7gk
D=m'pL/pl
//停止文件下载 #P l~R
public void siteStop() Ms~{9?
{ z|EEVNFd&
bStop = true; Sz- Jy:j
for(int i=0;i<nStartPos.length;i++) $6OkIP.
fileSplitterFetch.splitterStop(); WmY``
~cTN~<{dq
F *FwRj
} 3RLFp\i"s
} ^?7`;/
//负责部分文件的抓取 ;r_F[E2z
**FileSplitterFetch.java a,2'+Tlo
*/ 8V^oP]Y
package NetFox; x8S7oO7
-gSUjP
'EDda
import java.io.*; h$4Hw+Yxs]
import java.net.*; x=ul&|^7D
qlL`jWJ
TT=b79k
public class FileSplitterFetch extends Thread { ]E\n9X-{
Fa'k0/_j
T!Hb{Cg*
String sURL; //File URL [0"'T[ok
long nStartPos; //File Snippet Start Position Llr>9(|
long nEndPos; //File Snippet End Position Vn*tpbz
int nThreadID; //Thread's ID > ;/l)qk,
boolean bDownOver = false; //Downing is over Zt.'K(]2h
boolean bStop = false; //Stop identical Y. ,Kl~
FileAccessI fileAccessI = null; //File Access interface xx[9~z=d
ZI=%JU(
sZx/Ee
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException At-U2a#J{
{ $s9Vrw0Z
this.sURL = sURL; 'nXl>
this.nStartPos = nStart; C(00<~JC
this.nEndPos = nEnd; T:5fc2Ngv
nThreadID = id; Z.92y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $2W%2rZ
} (p2K36,9m
:xtXQza"-
:yUEkm8
public void run() /YZr~|65
{ xuqv6b.
while(nStartPos < nEndPos && !bStop) a)wJT`xu
{ ,%uo6%
eeyHy"@
i_j[?.?X}
try{ ;kY(<{2
URL url = new URL(sURL); &*+'>UEe5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "rx-_uK*
httpConnection.setRequestProperty("User-Agent","NetFox"); C?lcGt!H
String sProperty = "bytes="+nStartPos+"-"; mV3cp rRqv
httpConnection.setRequestProperty("RANGE",sProperty); _lamn}(x0
Utility.log(sProperty); V5UF3'3;}
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ogyTO|V=
InputStream input = httpConnection.getInputStream(); Vh_P/C+
//logResponseHead(httpConnection); i\,-oO
3j\1S1
,6-:VIHQ
byte[] b = new byte[1024]; Wk)OkIFR
int nRead; \O2Rhz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3B84^>U<
{ U4d:] z
nStartPos += fileAccessI.write(b,0,nRead); IZpP[hov
//if(nThreadID == 1) vEJWFoeEFm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 03q5e
} < jJ
OX\A|$GS
3yVMXK
Utility.log("Thread " + nThreadID + " is over!"); 59h)-^!
bDownOver = true; wB.&}p9p
//nPos = fileAccessI.write (b,0,nRead); C{U?0!^
} k?+?v?I =
catch(Exception e){e.printStackTrace ();} .yz}ROmN^
} E=nIRG|g
} vSEuk}pk
sS*3=Yh
E7rDa1
//打印回应的头信息 4 o Fel.o
public void logResponseHead(HttpURLConnection con) <0Xf9a8>
{ \W~N
for(int i=1;;i++) _h{C_;a[_
{ sB7# ~pA
String header=con.getHeaderFieldKey(i); Zy`m!]G]80
if(header!=null) h2G$@8t}I
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 16=sij%A
Utility.log(header+" : "+con.getHeaderField(header)); Sc;BCl{=|
else 4K\G16'$v
break; 8Vr%n2M
} o~`/_+
} nLXlU*ES
\NPmym_6J
VK m&iidU
public void splitterStop() '=b/6@&
{ {*G9|#[/@
bStop = true; qLD ?juas
} Q'=x|K#xj
dYJ(!V&
y [}.yyye
} IG2r#N|C#
F3On?x)
Te"ioU?.
/* $a.JSXyxL
**FileAccess.java h9}+l
*//文件访问(定位，写) v[1aWv:
package NetFox; :D~DU,e'
import java.io.*; -t!~%_WCv
'jWr<]3
| )K8N<n
public class FileAccessI implements Serializable{ V%rzk*LA
@>,^":`#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]cHgleHQ
RandomAccessFile oSavedFile; >g1~CEMN#
long nPos; q'T4w!V(V
>mwlsL~X
marQNZ
public FileAccessI() throws IOException hOjk3 k
{ j#!IuH\]
this("",0); cr7 }^s
} gb[5&>(#
M?1Y,5
f%][}NN)Xr
public FileAccessI(String sName,long nPos) throws IOException 6]K_m(F
{ %O|iE M
oSavedFile = new RandomAccessFile(sName,"rw"); Ag-(5:
this.nPos = nPos; 8\&X2[oAD
oSavedFile.seek(nPos); "g5^_UP
} <? q?Mn
*#,7d"6W5
"H'B*vc-
public synchronized int write(byte[] b,int nStart,int nLen) J!dm-L
{ D+lAhEN
int n = -1; .s?L^Z^
try{ #NEE7'&S
oSavedFile.write(b,nStart,nLen); L>jY.d2w=K
n = nLen; {'7B6
} - YEZ]:"
catch(IOException e) ha]VWt%}
{ ]E5o1eeg
e.printStackTrace (); xQ f*
} BtkOnbz8X
Ri<u/ ]oR"
)1?y 8_B
return n; X-bcQ@Oj
} r8`ffH
|mZxfI
0"jY.*_EW
} xG~P+n7t5$
ER%^!xA
.]8ZwAs=&
/* d[iQ`YW5
**SiteInfoBean.java bV^rsJm
*/ x]}^v#
package NetFox; S|Q@:r"
uy>q7C
lU8l}Ndz"
public class SiteInfoBean { }7b%HTF=
(~p< P+
; 5*&xz
private String sSiteURL; //Site's URL )3cAQ'w
private String sFilePath; //Saved File's Path j`{?OYD
private String sFileName; //Saved File's Name ">\?&0
private int nSplitter; //Count of Splited Downloading File 'g}!
<$D`Z-6
sA+ }TNhq
public SiteInfoBean() /:cd\A}
{//nSplitter的缺省值为5 P\E<9*V
//default value of nSplitter is 5 ]%;:7?5l
this("","","",5); 9)l$ aBa
} #|uCgdi
tHU2/V:R
U7?;UCmX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #]\Uk,mhZB
{ ^ gdaa>L
sSiteURL= sURL; ) ;EBz
sFilePath = sPath; tj'\tW+s'
sFileName = sName; on4HKeO
this.nSplitter = nSpiltter; iDpSj!x/_
mVj9,q0
./\@Km?
} y'3rNa]G1
2R[:]-b
sU=H&D99
public String getSSiteURL() D(~U6SR
{ Kew@&j~
return sSiteURL; z}.e]|b^H
} x'8x
p'Y^X
})'B<vq
public void setSSiteURL(String value) ,V7nzhA2
{ M`0V~P`^
sSiteURL = value; S;Fi?M
} {B~QQMEow
9=s<Ld
N:^n('U&j
public String getSFilePath() kXViWOXU^
{ EfqX y>W
return sFilePath; N"Z{5A
} t$`r4Lb9/
&j;wCvE4+
ez7A4>/
public void setSFilePath(String value) Mc)}\{J
{ aEB_#1
sFilePath = value; <;lkUU(WT2
} [|v][Hwv
\P[Y`LYL
)j6~Wy@4
public String getSFileName() ]>!K3kB
{ }H53~@WP>
return sFileName; Lw1Yvtn
} %mW{n8W3{
59LG{R2
Usvl}{L[
public void setSFileName(String value) d z|or9&
{ 28-RC>,@}
sFileName = value; {$oj.V 4
} <NMEGit
b1cy$I
#`^}PuQ
public int getNSplitter() (&r.w
{ [+^1.N
return nSplitter; p:&8sO!m
} "MeVE#O
-abt:or
*tA1az-jO
public void setNSplitter(int nCount) a .#)G[*
{ 9+|$$)
nSplitter = nCount; Q3'llOx
} +w`2kv
} jRa43ck
~g91Pr
#<fRE"v:Q
/* ZtNN<7
**Utility.java (g]!J_Z"
*/ 8\^R~K`sY
package NetFox; Xg6Jh``
9X6h
Ov@gh kr
public class Utility { 2Ah#<k-gC;
{p2!|A&a
cVv=*81\
public Utility() `bq<$e
{ w7L{_aom
b!t0w{^w
rI{; IDV
} Z-%\ <zT
ic:zsuEm
//线程睡眠 G[PtkPSJ
public static void sleep(int nSecond) ScOK)nL"
{ s S+MqBh&I
try{ }rUN_.n4z
Thread.sleep(nSecond); |"}FXaO
} "S[450%
catch(Exception e) (MM]N=Tw4
{ yZY\MB/
e.printStackTrace (); qz_7%c]K[
} LBeF&sb6
} 6q\bB
w{8xpAqm
//日志 j^sg6.Z*
public static void log(String sMsg) ;fTKfa
{ q>_.[+6
System.err.println(sMsg); I9A~Ye 5O&
} P8:dU(nlW
$S6`}3
s[>,X#7 y
public static void log(int sMsg) 7~h<$8Y(T
{ C^Yb\N}S
System.err.println(sMsg); -m zIT4
} +HpA:]#Y
} tU5zF.%
a=_g*OK}D
@D[_}JE
/* Y1\}5k{>
**TestMethod.java &&8x%Pml
*/ !qQl@jO
package NetFox; #P9~}JB3,
)u&|_&g{}J
d'gfQlDny
public class TestMethod { nF]W,@u"h
R_cA:3qc~
x;KOqfawv
public TestMethod() AR%4D3Dma
{ ///xx/weblogic60b2_win.exe Tk[ $5u*,
try{ p$c6<'UqH
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Dj?> <@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [85spub&}
SiteFileFetch fileFetch = new SiteFileFetch(bean); ($MlXBI
fileFetch.start(); @gEUm_#HTs
} D/gw .XYL
catch(Exception e){e.printStackTrace ();} .hb:s,0mP
5V~oIL
?4}h&/
} xIW3={b3
wU36sCo
Vm(y7}Aq{
public static void main(String[] args) Ml{,
{ p`dU2gV
new TestMethod(); 2a)xTA#
} s\(k<Ks
} &BLJT9Frx
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