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)); vr_Z0]4`C9
} bP4}a!t+n
for(int i=0;i<nEndPos.length-1;i++) 4"\%/kG
{ WzBr1 ea{I
nEndPos = nStartPos[i+1]; :kd]n$]
} v8C4BuwA
nEndPos[nEndPos.length-1] = nFileLength; 7'|aEH
} t8*NldC
} }?sC1]-j&
y!_8m#n S
3kVN[0
//启动子线程 6wZ)GLW[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =RQI5nHdw
for(int i=0;i<nStartPos.length;i++) $\PU Y8
{ as[! 9tB]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F#.ph?W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Hk=HO|&<XB
nStartPos,nEndPos,i); r4b-.>w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S7~HBgS<
fileSplitterFetch.start(); }eveNPB{5
} >G As&\4hs
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .-Dc%ap]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); al7D3J
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >qd=lm <,
nEndPos = " + nFileLength); buhbUmQ2
// fileSplitterFetch[nPos.length-1].start(); NnaO!QW%
K@a#^lmd
xT!<x({
//等待子线程结束 QH?sx k2
//int count = 0; Bi>]s%zp
//是否结束while循环 _7dp(R
boolean breakWhile = false; ,,lR\!>8
"CZv5)
uJ0Wb$%
while(!bStop) }^^c/w_
{ "+Sq}WR
write_nPos(); _z9~\N/@[
Utility.sleep(500); F6C7k9
breakWhile = true; |f(*R_R
"akAGa!V+
lR]FQnZ
for(int i=0;i<nStartPos.length;i++) @|e we.r
{ kU.@HJ[@j
if(!fileSplitterFetch.bDownOver) Qraa0]56
{ #qeC)T
breakWhile = false; 6E.[F\u
break; s-~`Ao' <
} DgB;6Wl
} _/Ay$l;F
if(breakWhile) `g0^W/j
break; ES8(:5
\r [@A3O
]bYmM@
//count++; g1(5QWb
//if(count>4) +[4y)y`
// siteStop(); U]g9t<jD
} ab]Q1kD
hFxT@I~
wc&D[M]-/
System.err.println("文件下载结束！"); 7NnXt'
} A;o({9VH`Z
catch(Exception e){e.printStackTrace ();} ~ H/ZiBL@
} >qmNT/
DfVJ~,x~
O- LwX >
//获得文件长度 M}q;\}
public long getFileSize() '`f+QP=`
{ C &y 2I
int nFileLength = -1; c;zk{dP
try{ OXn-!J90P
URL url = new URL(siteInfoBean.getSSiteURL()); O,S>6o)?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UT[{NltH
httpConnection.setRequestProperty("User-Agent","NetFox"); $xcZ{C
;' H\s
[JV?Mdzu
int responseCode=httpConnection.getResponseCode(); 4t3>`x 7
if(responseCode>=400) s!>9od6^
{ W=OryEV?
processErrorCode(responseCode); (@;^uVJP
return -2; //-2 represent access is error <RtyW
} m9+?>/R
PZlPC#E-
bm4Bq>*=U
String sHeader; kE|x'(x
#)]/wqPoW
mIqm/5
for(int i=1;;i++) =E^/gc%X
{ I5`>XfO)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G;EJ\J6@Yw
//Utility.log(in.readLine()); 23 #JmR
sHeader=httpConnection.getHeaderFieldKey(i); t*H|*L#YR
if(sHeader!=null) ^7Z;=]8J
{ %b2Hm9r+
if(sHeader.equals("Content-Length")) e,lLHg
{ ]E'?#z.t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !nlr!+(fV
break; L 4Z+8*
} {FS)f
} #;?/fZjY
else q8FpJ\
break; rS8\Vf]F
} 'GiN^Y9dcc
} .w'b%M
catch(IOException e){e.printStackTrace ();} -=5~-72~
catch(Exception e){e.printStackTrace ();} ?/-WH?1I
]cVDXLj$
DbX7?Jr
Utility.log(nFileLength); ]yL+lv
;jN1n xF
=1'WZp}D5
return nFileLength; bf{_U%`
} ,np|KoG|M
5FF28C)>/
65*Hf3~~
//保存下载信息（文件指针位置） w{So(AF
private void write_nPos() Q1rEUbvCE
{ '>n&3`r5
try{ hw*u.46
output = new DataOutputStream(new FileOutputStream(tmpFile)); *c&OAL]
output.writeInt(nStartPos.length); LZ.Xcy
for(int i=0;i<nStartPos.length;i++) A1`6+8}o;b
{ aw~h03R_Z
// output.writeLong(nPos); *::.Uo4O
output.writeLong(fileSplitterFetch.nStartPos); ,v#n\LD`
output.writeLong(fileSplitterFetch.nEndPos); dUl"w`3
} kqxq'Aq)d
output.close(); pl)?4[`LUc
} AO|1m$xf
catch(IOException e){e.printStackTrace ();} wu`+KUx
catch(Exception e){e.printStackTrace ();} U^%)BI
} Fq5u%S
! Vlx
I,HtW),
//读取保存的下载信息（文件指针位置） e6 x#4YH
private void read_nPos() /e^) *r
{ )N607 Fa-
try{ 5MKM;6cA&p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |v5 ge3-
int nCount = input.readInt(); ~I%164B+/
nStartPos = new long[nCount]; nZ(wfNk
nEndPos = new long[nCount]; =&qH%S6
for(int i=0;i<nStartPos.length;i++) >5"e<mwD7d
{ E)f9`][
nStartPos = input.readLong(); f?ibyoXL
nEndPos = input.readLong(); 8oXp8CC
} qswC>Gi
input.close(); ( ^@i(XQ
} '}B"071)<
catch(IOException e){e.printStackTrace ();} 1s(]@gt
catch(Exception e){e.printStackTrace ();} ~K99DK.
} M_.Jmh<&&
m%>}T75C^
_nEVmz!zg
private void processErrorCode(int nErrorCode) ;134$7!Y
{ +zq"dj_
System.err.println("Error Code : " + nErrorCode); 3S2Alx!6
} #7}M\\$M
ZH8w^}
(_CvN=A
//停止文件下载 ^FBu|eAkE
public void siteStop() CSq|R-@<U
{ ?Tu=-ppw
bStop = true; &}7R\co3
for(int i=0;i<nStartPos.length;i++) JtxVF!v
fileSplitterFetch.splitterStop(); EzjK{v">
N5ZOpRH{
1_v\G
} _z{9V7n4
} vNuws_
//负责部分文件的抓取 ITTEUw~+o
**FileSplitterFetch.java EG$-D@o\I
*/ W6i9mER-
package NetFox; W*CRxGyZCl
VwZ~ntk
;in-)`UC!
import java.io.*; :yJ([
import java.net.*; cfa1"u""e
B@0#*I Rm
~>lqEa
public class FileSplitterFetch extends Thread { Bp5ra9*5+~
9+s&|XS*
|9IOZ>H9
String sURL; //File URL l&e$:=;8
long nStartPos; //File Snippet Start Position 3oH/34jj
long nEndPos; //File Snippet End Position q*` m%3{
int nThreadID; //Thread's ID qQG? k~r
boolean bDownOver = false; //Downing is over ~u2f`67{
boolean bStop = false; //Stop identical ruB D ^-
FileAccessI fileAccessI = null; //File Access interface g<M!]0OK
C58o="L3S
j>:N0:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7Re\*[)T
{ CMOyK^(e
this.sURL = sURL; .74C~{}$
this.nStartPos = nStart; Pmd[2/][
this.nEndPos = nEnd; 0H^*VUyW/
nThreadID = id; Fb8d=Zc
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hhZ%{lqL
} " M?dU^U^
.Wy'
PuGs%{$(h
public void run() &Mudu/KTr
{ H)gc"aRe;Y
while(nStartPos < nEndPos && !bStop) 5|K[WvG@Co
{ "G.X=, V
U4K ZPk
Cb+$|Kg/"b
try{ "0#(<zb|
URL url = new URL(sURL); !bYVLFp=\_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ry]9n.y
httpConnection.setRequestProperty("User-Agent","NetFox"); QSa#}vCp*
String sProperty = "bytes="+nStartPos+"-"; R2-F@_
httpConnection.setRequestProperty("RANGE",sProperty); 3e1-w$z&S
Utility.log(sProperty); {j]cL!Od
43M.Hj]
bo\Ah/.
InputStream input = httpConnection.getInputStream(); Q*PcO\Y!y
//logResponseHead(httpConnection); w?|qKO
; YQB
SE^l`.U@
byte[] b = new byte[1024]; :?g+\:`/0j
int nRead; ,@?9H ~\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) };9s8VZE
{ ,h'Q
nStartPos += fileAccessI.write(b,0,nRead); iCg%$h
//if(nThreadID == 1) e"eIQI|N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E7? n'!=
} j<0;JAL
{2P18&=
ux(~+<k
Utility.log("Thread " + nThreadID + " is over!"); `pZX!6Wn
bDownOver = true; Z.Z;p/4F
//nPos = fileAccessI.write (b,0,nRead); C`kqsK
} ~//E'V-
catch(Exception e){e.printStackTrace ();} wLqj<ot
} J@_^]
} _",(!(
L@6]~[JvP
KhB775
//打印回应的头信息 ^GY^g-R
public void logResponseHead(HttpURLConnection con) O)VcW/
{ 5!qf{4j
for(int i=1;;i++) *p\Zc*N;%
{ ;)CN=J!
String header=con.getHeaderFieldKey(i); O(8CrKYY
if(header!=null) u_9c>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ui#nN
Utility.log(header+" : "+con.getHeaderField(header)); .Hqq!&
else 5= &2=
break; kG!hqj
} xlwf @XW
} T:{r*zLSN
[(#)9/3,
# M/n\em"X
public void splitterStop() 'hBnV xd&
{ !JrKTB%
bStop = true; hZ e{Ri
} 5yoi;$~}_0
M NwY
f7Nmvla[q
} Ul]7IUzsu
`j)56bR
W5`pQdk
/* ?VE'!DW
**FileAccess.java l_:P|
*//文件访问(定位，写) Nr>UZlU8
package NetFox; b:Zh|-
import java.io.*; c]#}#RJ`\
*.>@
-sJD:G,%
public class FileAccessI implements Serializable{ bs~P
C@`#@1X
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Icg-rwa<Z
RandomAccessFile oSavedFile; b,~pwbHf
long nPos; ^t gjs$M|
-`\rDPGf
E#rQJ
public FileAccessI() throws IOException vMou`[\WlJ
{ ,s3|
this("",0); 6&SNFOX{@
} zytN leyc
^"?a)KC
{q8|/{;
public FileAccessI(String sName,long nPos) throws IOException :+jg311}
{ `&q+ f+z
oSavedFile = new RandomAccessFile(sName,"rw"); {u1|`=;
this.nPos = nPos; Lr*PbjQDIY
oSavedFile.seek(nPos); :K2 X~Ty
} $#D#ezvxe
~"`e9Im
mp$IhJ6#
public synchronized int write(byte[] b,int nStart,int nLen) `Pj7:[."[
{ er3~gm
int n = -1; ^lV}![do!
try{ V>)/z|[
oSavedFile.write(b,nStart,nLen); MSM8wYcD
n = nLen; dyn)KDS
} ~%>i lWaHB
catch(IOException e) *'8q?R?7g
{ dNt^lx
e.printStackTrace (); vkGF_aenk
} |wuTw|
\X*y~)+K`
LZ_VLW9wE
return n; ,S`n?.&& 7
} 5O]tkHYR
p )JR5z
@Drl5C}+
} SQK82/
8ly)G
K(upzn*a
/* us|Hb
**SiteInfoBean.java 1DcBF@3sWG
*/ >^g2Tg:
package NetFox; QEt"T7a[/
(jU_lsG
UwS7B~
public class SiteInfoBean { Iga+8k
Y2l;NSWU
8o|C43Q_
private String sSiteURL; //Site's URL ;AOLbmb)H4
private String sFilePath; //Saved File's Path =bD.5,F)
private String sFileName; //Saved File's Name uNuFD|aQ.
private int nSplitter; //Count of Splited Downloading File T=-UcF
y-.{){uaD
\v-I<"::
public SiteInfoBean() au50%sA~
{//nSplitter的缺省值为5 U'" #jT
//default value of nSplitter is 5 [#@lsI
this("","","",5); %zGv+H?
} y$-@|M$GG
}W 5ks-L6
u5ZyOZ;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @u/CNx,`X
{ l@GJcCufE
sSiteURL= sURL; hE=xS:6
sFilePath = sPath; OV;VsF
sFileName = sName; "A Bt
this.nSplitter = nSpiltter; T_Tu>wQX
!~?/D
"0PsCr}!
} {u y^Bui}
b?`2LAgn
#|je m
public String getSSiteURL() $6UU58>n
{ jcj8w
return sSiteURL; N}n3 +F
} CQ6I4k
H0"'jd
Wm-$l
public void setSSiteURL(String value) %D#&RS
{ <v -YMk@
sSiteURL = value; y(g]:#
} M.y!J
Ddq*}Pf0K
J2x}@p
public String getSFilePath() 9b=0 4aWHm
{ Z|*#)<|~
return sFilePath; l9|K,YVW
} E]n]_{BN]
HEFgEYlO
T8g\_m
public void setSFilePath(String value) O0'|\:my
{ O6?{@l
sFilePath = value; IYq#|^)5+
} =C,DR4xh
0^V<,CAV
7NT} Zwf
public String getSFileName() a"YVr'|
{ 9jf9u0
return sFileName; V]J"v#!{
} D<FQVdP
WynTU?
.^=I&X/P
public void setSFileName(String value) u(1m#xr8$
{ dDl+
sFileName = value; :35h0;8+
} @a]cI
3t+{~{Dj
9Cd/SlNV2
public int getNSplitter() BQWgL
{ KxKZC}4m
return nSplitter; N{g7
} ,m`&J?
E)m \KSwh
Dx /w&v
public void setNSplitter(int nCount) \H>T[
{ ,_(=w.F
nSplitter = nCount; ~cp=B>*(
} *LBF+L^C%
} nkPlfH
\9p.I?=
[I%eRo[
/* Jxe5y3* (
**Utility.java #y#TEw,
*/ X1P1 $RdkR
package NetFox; 4.,|vtp
] +%`WCr9
z6M5'$\y
public class Utility { ^,=}'H]
~28{BY
[>GblL
public Utility() v `/nX->
{ cu?6\@cD
Xp<O
%KO8i)n
} 5s^vC2$)
Wx3DWY;
//线程睡眠 lt4IoE`tk?
public static void sleep(int nSecond) _z%\53h
{ V+1c<LwT
try{ r0k:RJP
Thread.sleep(nSecond); x1wD`r
} H(n fHp.3
catch(Exception e) S"Vr+x?
{ *^]
e.printStackTrace (); ~2hzyEh
} Q`J U[nY
} W?E01"p
y=\&z&3$
//日志 :tFcPc'
public static void log(String sMsg) e^\(bp+83
{ ]6v7iuvI
System.err.println(sMsg); xv$fw>
} LC=M{\
K%%Ow
3`SH-"{j%
public static void log(int sMsg) %jj-\Gz!
{ )ZLj2H<
System.err.println(sMsg); !p\ @1?
} /J-.K*xKt
} &,p6lbP
K($+ILZ
})@xWU6!
/* C<:wSS^@1
**TestMethod.java 0# 1~'e
*/ P;y!Y/$C
package NetFox; ^=-25%&^
lws.;abm%n
!}P^O(oY
public class TestMethod { @/As|)
D.7cWR`Wp
B(71I;
public TestMethod() |uFb(kL[U
{ ///xx/weblogic60b2_win.exe l#ct;KZ
try{ g1F9IB42@<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); nw*a?$S3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {s*1QBM$\Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~a7@O^q4
fileFetch.start(); \hlS?uD\
} h Ks
catch(Exception e){e.printStackTrace ();} Wn;%B].I
'^7Z]K<v
G~&q
} :G9d,B7*
dwvc;f-
vfc5M6Vm)<
public static void main(String[] args) H 9/m6F
{ er 1zSTkg
new TestMethod(); `3K."/N6c
} IYptNR
} UZiL NKc
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