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)); e&|'I"
} s[RAHU
for(int i=0;i<nEndPos.length-1;i++) 4M=]wR;
{ \#2Z)Kz
nEndPos = nStartPos[i+1]; c?(4t67|
} !P2ro~0/
nEndPos[nEndPos.length-1] = nFileLength; 4qb/daE:Z
} L4@K~8j7
} %^)fmu
e@L=LW>
9@SC}AF.
//启动子线程 :(E@Gf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sNbxI|B
for(int i=0;i<nStartPos.length;i++) a(m2n.0'>
{ lF<]8m%F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sf:,qD=z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +C^nO=[E
nStartPos,nEndPos,i); HDz5&7* .
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =Pyj%4Rs
fileSplitterFetch.start(); U45e2~1!O
} #>a\>iKQ2q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BwN0!lsF3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DHg:8%3x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @JiLgIe`
nEndPos = " + nFileLength); 7zl5yKN
// fileSplitterFetch[nPos.length-1].start(); D5gFXEeh
k`cfG\;r
[@_Jj3`4
//等待子线程结束 6lZ3tdyNo
//int count = 0; IY1//9
//是否结束while循环 ]]HNd7Vh
boolean breakWhile = false; Ky`qskvu
`{8K.(])s!
;gD})@
while(!bStop) p .%]Q*8
{ HRpte=`q
write_nPos(); eYc$dPE
Utility.sleep(500); mwO6g~@`
breakWhile = true; NYhB'C2
Q@=Q0
ynp8rf
for(int i=0;i<nStartPos.length;i++) `T1
{ M^A48u{,"
if(!fileSplitterFetch.bDownOver) 05|=`eJ
{ xnjf
breakWhile = false; s$IDLs,WM
break; xKbXt;l2
} g/4[N{Xf
} y-Fo=y
if(breakWhile) >:SHV W
break; zxEL+P
}ZYd4h|g\z
)',R[|<
//count++; ip\sXVR
//if(count>4) [\]50=&
// siteStop(); SV4E0c>
} .C%<P"=J4h
1> ?M>vK
gE-tjoJ
System.err.println("文件下载结束！"); ]dVGUG8
} #-rH1h3*q
catch(Exception e){e.printStackTrace ();} _r#Z}HK
} !6 #X>S14
XE RUo
I]|Pq
//获得文件长度 YO`]UQ|dc
public long getFileSize() 'B$yo]
{ x%=si[P
int nFileLength = -1; Xc++b|k
try{ t mntp
URL url = new URL(siteInfoBean.getSSiteURL()); 3=#<X-);
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O *C;Vqt
httpConnection.setRequestProperty("User-Agent","NetFox"); h#I>M`|
Xxj- 6i
O;Rqv
int responseCode=httpConnection.getResponseCode(); ]2A^1Del
if(responseCode>=400) =}^9 wP
{ 2YL?,uLS
processErrorCode(responseCode); >-?f0K
return -2; //-2 represent access is error !vi>U|rh
} bG"~"ipn%
t|?ez4/{z
|T /ZL!
String sHeader; HdI8f!X'TG
OG~gFZr)6
Oamg]ST
for(int i=1;;i++) gk4;>}
{ 0q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Oxnp0 s
//Utility.log(in.readLine()); u]wZQl#-
sHeader=httpConnection.getHeaderFieldKey(i); ;<Sd~M4f
if(sHeader!=null) 2>9C-VL2
{ )iX~}7
if(sHeader.equals("Content-Length")) <V'@ks%
{ \&:nFb%=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~Gp[_ %K
break; OnziG+ak
} yu {d! {6
} P{`C^W$J^
else v~+(GqR=+
break; ~D+bh~
} <{p4V|:
} )* :gqN
catch(IOException e){e.printStackTrace ();} GAzU?a{S
catch(Exception e){e.printStackTrace ();} w(Ovr`o?9t
f)rq%N &
5pG}Yk_(x
Utility.log(nFileLength); 5ta `%R_
JG.y,<xW
V-P#1Kkh
return nFileLength; P:S.~Jq
} atH*5X6d
~At7 +F[
+/7?HGf
//保存下载信息（文件指针位置） hag$GX'2k
private void write_nPos() GVr1`l
{ y7cl_rK
try{ s[*rzoA
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0o4XUW
output.writeInt(nStartPos.length); Wb_J(!da
for(int i=0;i<nStartPos.length;i++) -IudgO]
{ G>=*yqo
// output.writeLong(nPos); //MUeTxR
output.writeLong(fileSplitterFetch.nStartPos); l30EKoul)
output.writeLong(fileSplitterFetch.nEndPos); X`/k)N>l
} ]q[D>6_
output.close(); aK~8B_5k8
} P;no?
catch(IOException e){e.printStackTrace ();} t3ZOco@~P
catch(Exception e){e.printStackTrace ();} }&D WaO]J7
} 59L\|OR
bWS&Yk(
O\tb R=
//读取保存的下载信息（文件指针位置） S+6.ZZ9c
private void read_nPos() Y-z(zS^1
{ #z%fx
try{ {fM'6;ak
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ">nxHU
int nCount = input.readInt(); VGN5<?PrN
nStartPos = new long[nCount]; #%2rP'He
nEndPos = new long[nCount]; Z\rwO>3
for(int i=0;i<nStartPos.length;i++) {Mk6T1Bkq
{ ^DLfY-F+j
nStartPos = input.readLong(); VQ@
nEndPos = input.readLong(); Q{>k1$fkV
} KF}hV9IU
input.close(); -i|}m++
} ~8+ Zs
catch(IOException e){e.printStackTrace ();} y.k~Y0
catch(Exception e){e.printStackTrace ();} JR|ck=tq
} >Tx?%nQ
XT*sGM
3}1u\(Mf
private void processErrorCode(int nErrorCode) h#*dI`>l-
{ o-HT1Hc!
System.err.println("Error Code : " + nErrorCode); e9tjw[+A
} gJ{)-\
6MW{,N
~~P5k:
//停止文件下载 (CL%>5V
public void siteStop() 0+ '&`Q!u
{ T-L||yE,h
bStop = true; Zi i
for(int i=0;i<nStartPos.length;i++) l)\! .X
fileSplitterFetch.splitterStop(); ru%y
#{6/ (X
3hH<T.@)
} _H%c;z+
} w&#]-|$
//负责部分文件的抓取 '<<t]kK[N
**FileSplitterFetch.java NI]N4[8(
*/ (ZizuHC
package NetFox; BWrxunHO
Avc%2+
_{KG 4+5\X
import java.io.*; O/Crd/
import java.net.*; p2](_}PK
{\5
L2z[
public class FileSplitterFetch extends Thread { # W']6'O
Sm|6 %3
2ilQXy
String sURL; //File URL tWRC$
long nStartPos; //File Snippet Start Position r19 pZAc
long nEndPos; //File Snippet End Position IJ"q~r$
int nThreadID; //Thread's ID S2VVv$r_6
boolean bDownOver = false; //Downing is over k 2%S`/:
boolean bStop = false; //Stop identical d=]U_+
FileAccessI fileAccessI = null; //File Access interface !z zW2>
7CB#YP?E
wn11\j&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Kt.~aaG_
{ m$$?icA
this.sURL = sURL; ~mN%(w!^
this.nStartPos = nStart; sst,dA V$
this.nEndPos = nEnd; uC]Z8&+obb
nThreadID = id; '?GQ~Bf<>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 G7* h{nE
} I2HT2c$
[ev-^[
.%0ne:5
public void run() 1:= `Y@.S
{ 2#_38=K=@
while(nStartPos < nEndPos && !bStop) =<<3Pkv7@
{ hGP1(pH.
3LlU]
|&hU=J o
try{ i!MwBYk
URL url = new URL(sURL); n!N\zx8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z4} %TT@^
httpConnection.setRequestProperty("User-Agent","NetFox"); nb@"?<L!
String sProperty = "bytes="+nStartPos+"-"; qvLDfN
httpConnection.setRequestProperty("RANGE",sProperty); |j_`z@7(
Utility.log(sProperty); IvW@o1Q
U 0ZB^`
F1A1@{8bN
InputStream input = httpConnection.getInputStream(); 9[|4[3K
//logResponseHead(httpConnection); BGjb`U#%3
te2 Iu%5 z
+*t|yKO>[
byte[] b = new byte[1024]; u+% tPe
int nRead; Gidkt;lj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FpkXOj?*
{ {~GR8 U
nStartPos += fileAccessI.write(b,0,nRead); i@$-0%,
//if(nThreadID == 1) wR7aQg
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '>^Xqn
} i;lE5
_IYY08&(r
w6EI{
Utility.log("Thread " + nThreadID + " is over!"); ]A!.9Ko}u
bDownOver = true; -fux2?8M
//nPos = fileAccessI.write (b,0,nRead); /{G/|a
} H%Y%fQ~^
catch(Exception e){e.printStackTrace ();} PqhlXqX9
} 5V|tXsy:
} &`PbO
RWahsJTu
31 ]7z
//打印回应的头信息 M1uP\Sa
public void logResponseHead(HttpURLConnection con) !Y%D 9
{ deM~[1e[
for(int i=1;;i++) n|]N7 b'
{ 4!2SS
String header=con.getHeaderFieldKey(i); +(AwSh!
if(header!=null) +{xG<Wkltz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z1]"[U[;
Utility.log(header+" : "+con.getHeaderField(header)); WLy7'3@
else 6{^*JC5nj
break; >q&L/N5
} qP`?M\!O
} 3"B+xbe=
HWR&C
t~~r-V":
public void splitterStop() R1 qMg+
{ -4`sqv ]
bStop = true; 36i_D6
} 7xR|_+%~K
ok=40B99T
GG>Y/;^
} Wy,"cT
(lb`#TTGx
165WO}(;/
/* eU"mG3__
**FileAccess.java />!!ch
*//文件访问(定位，写) q"p#H8
package NetFox; k7b(QADqUU
import java.io.*; >";%2u1
2q|_Dma
:28@J?jjO
public class FileAccessI implements Serializable{ vF+YgQ1H
1YFAr}M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %g5jY%dg.r
RandomAccessFile oSavedFile; ~W/}:;
long nPos; mC"7)&,F
C*]AL/
3v G
public FileAccessI() throws IOException _dY:)%[]
{ M;> ha,x
this("",0); {z-NlH
} 0 c,bet{m
&8juS,b
! 7Nn]Lx
public FileAccessI(String sName,long nPos) throws IOException e8 v; D
{ I@+lFG
oSavedFile = new RandomAccessFile(sName,"rw"); 7ia"u+Y
this.nPos = nPos; B_b8r7Vn`
oSavedFile.seek(nPos); dkf}),Z F
} oNrEIgaA(+
wiKCr/
jf2y0W>6s
public synchronized int write(byte[] b,int nStart,int nLen) ?!_u,sT
{ ?TRW"%
int n = -1; 2}GKHC
try{ -Zttj/K
oSavedFile.write(b,nStart,nLen); IBzHR[#,^
n = nLen; il=?of\,i
} uFMs^^#
catch(IOException e) @_G` Ok4
{ GsR-#tV@
e.printStackTrace (); X"laZd947>
} wYC9~ms-
sn2r>m3
#^"hqNwA
return n; \-DM-NrZ1U
} 7^`RP e^a+
30t:O&2<
[>Ikitow
} ojiM2QT}m
#tCIuQ,
[B.W1 GL!
/* 4u7c7K>\Y
**SiteInfoBean.java kOo>Iy
*/ (D:KqGqoT
package NetFox; ]v/t8`
<m-Ni
kO /~i
public class SiteInfoBean { dOYlI`4
1Kp?bwh"u
l#mqV@?A~
private String sSiteURL; //Site's URL >\N$>"~a
private String sFilePath; //Saved File's Path d@_'P`%-
private String sFileName; //Saved File's Name *Cc$eR]-
private int nSplitter; //Count of Splited Downloading File I^6c0`
/&y,vkZTT
5%vP~vy_}
public SiteInfoBean() c80"8r
{//nSplitter的缺省值为5 \ x>NB
//default value of nSplitter is 5 $`cy'ZaF
this("","","",5); |DdW<IT`0
} Z&2 &wD
#c8"
NZC<m$')
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w*]_FqE
{ TXY
sSiteURL= sURL; ?S;et2f
sFilePath = sPath; !XG/,)A
sFileName = sName; C.B8 J"T-
this.nSplitter = nSpiltter; B8P@D"u
$D0)j(v
S^_JC
} #t5JUi%in*
z*:^*,
yHCBf)N7\
public String getSSiteURL() eI- ~ +.
{ <jV_J+#
return sSiteURL; REw!@Y."
} .Emw;+>
Hq=RtW2
QQqWJq~
public void setSSiteURL(String value) i2EB.Zlv
{ y>|7'M*+
sSiteURL = value; Dk:Zeo]+my
} Ry,jPw5<
JI(8{ f
\s[Uq
public String getSFilePath() 1'M<{h<sP
{ g!4"3Dtdg
return sFilePath; P*G&pitT
} Kx ';mgG#$
xEGI'lt
|Zz3X
public void setSFilePath(String value) `XQM)A
{ 'H:lR1(,
sFilePath = value; iz>a0~(K
} <Cm:4)~
s(F^P
.BZw7 YV
public String getSFileName() jPhOk>m
{ Z{&PKS
return sFileName; 3. fIp5g
} RytQNwv3
!\^c9Pg|v
WC0@g5;1[
public void setSFileName(String value) 3Cq17A 9
{ "@DCQ
sFileName = value; #NwlKZ-
} F(:+[$)
h$y1"!N(
G ?H`9*y
public int getNSplitter() Fod2KS;g
{ t: r
return nSplitter; |{<g-)
} &$|k<{j[<f
s9zdg"c'
UPA))Iv>
public void setNSplitter(int nCount) r)q6^|~47
{ Jcy
nSplitter = nCount; mq do@
} aa8WRf
} K>"M#T
Wl?*AlFlk
W_ngB[
/* l0 rZril
**Utility.java 9co1+y=i{
*/ 2>_6b>9]
package NetFox; 2(Vm0E
9Ld3
/|bir6Y:
public class Utility { z<hy#BIjnd
;Z%ysLA
h)~KD%
public Utility() l%oie1g l
{ }[SWt3qV1
>t20GmmN
/xWkP{
} Y7zg
D: NBb!
//线程睡眠 x@;XyQq
public static void sleep(int nSecond) cO.U*UTmX
{ G29PdmY$<
try{ QS4sSua
Thread.sleep(nSecond); J$%mG*Y(
} qH: ` O%,
catch(Exception e) *!ZU"q}i
{ G^ZL,{
e.printStackTrace (); NIY0f@1z-
} 5hUYxF20h8
} Zz'(!h Uy
MMqkNe
//日志 Ou"QUn|
public static void log(String sMsg) (wdE@/V
{ s/Fc7V!;
System.err.println(sMsg); Cg |_) _w
} |FHeT*"
7[rn ,8@
KdHR.;*
public static void log(int sMsg) AU)"L_ i}
{ Z3<>Z\6D
System.err.println(sMsg); cKEf- &~
} d kHcG&)
} +AhR7R!
(YVl5}V
0(VH8@h`O
/* TG8QT\0G
**TestMethod.java T^B&GgW
*/ [u;]J*
package NetFox; ^W5rL@h_
a,b;H(em
$qYtN`b,
public class TestMethod { UK*+EEv
1_%jDMYH
A)Wp W M
public TestMethod() )HNbWGu
{ ///xx/weblogic60b2_win.exe Z#BwJHh
try{ l~!Tnp\M
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _6Wz1.]n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); VQ5T$,&
SiteFileFetch fileFetch = new SiteFileFetch(bean); $,otW2:)
fileFetch.start(); {:xINQ=}D
} lBqu}88q0
catch(Exception e){e.printStackTrace ();} 7Oe |:Z
GzWmXm
?`V%[~4_I
} 1fM=>Z
IE.JIi^w
G,9osTt/
public static void main(String[] args) ,LKY?=T$z
{ -U)6o"O_CV
new TestMethod(); `=Pn{JaD
} m:5*:Ii.
} y K)7%j!
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