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)); Ble <n6
} ^*Ca+22xO
for(int i=0;i<nEndPos.length-1;i++) "--rz;+K
{ Qs~;?BH&
nEndPos = nStartPos[i+1]; d,$[633It}
} [t0gXdU6
nEndPos[nEndPos.length-1] = nFileLength; @O4m-Oosi
} ~(FyGB}
} l_$~~z ~
MF=@PE][
TG'A'wXxy
//启动子线程 vZ|m3;X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; hv9s
for(int i=0;i<nStartPos.length;i++) Z>o20uA
{ A/GEDG ?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dGZVWEaPfx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xH*OEzN
nStartPos,nEndPos,i); \<V{6#Q=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vk{dL'
fileSplitterFetch.start(); IUI>/87u
} )=8X[<^i
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HSyohP87
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <Y9ps`{}:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;c~6^s`2
nEndPos = " + nFileLength); w!tQU9+*
// fileSplitterFetch[nPos.length-1].start(); HHT K{X+
0hCJovSG%
MX qH
//等待子线程结束 ,p0R4gi
//int count = 0; O'o`
//是否结束while循环 2v yB[(
boolean breakWhile = false; ]yA| m3^2
[O9(sWL'
L1M]ya!l
while(!bStop) C$Ldz=d
{ 389T6sP]
write_nPos(); ?GX5Pvg
Utility.sleep(500); pX|\J>u)
breakWhile = true; mG\,T3/*
7w YSP&$
;,4Z5+
for(int i=0;i<nStartPos.length;i++) [\eUCt F
{ Hz!+g'R!Gs
if(!fileSplitterFetch.bDownOver) zN*/G6>A
{ ;OE{&
breakWhile = false; Peh(*D{
break; 1u'x|Un
} }G_ i+
} @4_W}1W
if(breakWhile) hP,SvN#!2
break; tk2B\}6
Hk(w\
5fSDdaO
//count++; 3Ud&B
//if(count>4) {b8!YbG
// siteStop(); !G Z2|~f9
} tihb38gE
+.mIC:9
A<QYW,:|
System.err.println("文件下载结束！"); l&^9<th
} CSR6
catch(Exception e){e.printStackTrace ();} :$j!e#?=
} 0q>f x
(SU*fD!t
?7YX@x
//获得文件长度 [AfV+$
public long getFileSize() R1\cAP^0
{ (+q?xwl!N
int nFileLength = -1; z@{|Y;s
try{ LPvyfD;Zy
URL url = new URL(siteInfoBean.getSSiteURL()); G]=U=9ZI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4cTJ$" v
httpConnection.setRequestProperty("User-Agent","NetFox"); 'w^1re=R
Z#3wMK~
DbH{; Fb
int responseCode=httpConnection.getResponseCode(); Wi'BX#xCB
if(responseCode>=400) gXE'3
{ ?so3Kj6H
processErrorCode(responseCode); 2u~0B +)K/
return -2; //-2 represent access is error hm&{l|u{RU
} P)tXU
j}X4#{jgC
hSQP '6
String sHeader; |Gzd|$%Oq
kZWc(LwA
p}}}~ lC/
for(int i=1;;i++) L/c$p`-
{ ec)G~?FH
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YEF%l'm(\
//Utility.log(in.readLine()); 0/#XUX 4
sHeader=httpConnection.getHeaderFieldKey(i); {(7Dz*0
if(sHeader!=null) F C2oP,
{ Q{Jz;6"
if(sHeader.equals("Content-Length")) 9 %,_G.
{ Mw\/gm_3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;#G>qo
break; '.#KkvE##
} d9R0P2
} (|I0C 'Ki
else fFqK.^Tn
break; {MO`0n; rt
} q}M^i7IE
} AA^3P?iD
catch(IOException e){e.printStackTrace ();} s^AQJ{X
catch(Exception e){e.printStackTrace ();} hOO)0IrIM*
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ahhVl=9/ao
Utility.log(nFileLength); `g6ZhG:W
|*Z'WUv
WvAl!^{`
return nFileLength; R =mawmQ2
} H \.EKZ
Z@t).$
(=)+as"u9*
//保存下载信息（文件指针位置） ZBJ.dK?Ky|
private void write_nPos() IgLP=mqcWK
{ 8Nd +
try{ z }R-J/xr2
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4<ER dP7"-
output.writeInt(nStartPos.length); V.1sb pI
for(int i=0;i<nStartPos.length;i++) sog?Mvoq
{ f]J?-ks
// output.writeLong(nPos); aS'G&(_
output.writeLong(fileSplitterFetch.nStartPos); z=?ainnKx
output.writeLong(fileSplitterFetch.nEndPos); #Ru+|KL
} x*}(l%[
output.close(); 2a (w7/W:
} x|F6^d
catch(IOException e){e.printStackTrace ();} Jn'q'+
catch(Exception e){e.printStackTrace ();} fx99@%Ii
} RgRyo
|uj1T=ZY
(|(Y;%>-v
//读取保存的下载信息（文件指针位置） QI0ARdS
private void read_nPos() /+JCi6{sHS
{ RLw=y{%p
try{ P]yER9'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wrK$ZO]
int nCount = input.readInt(); qWw@6VvoQ
nStartPos = new long[nCount]; o7DDL{iR/
nEndPos = new long[nCount]; dK|MQ <
for(int i=0;i<nStartPos.length;i++) No=f&GVg
{ h'MX{Wm.
nStartPos = input.readLong(); [9'5+RXw3
nEndPos = input.readLong(); ;yBq'_e3
} m-, '
input.close(); rnmWw#
} d0MX4bhZ
catch(IOException e){e.printStackTrace ();} y?_tSnDK
catch(Exception e){e.printStackTrace ();} Y0&w;P
} 4JU#3
&7E0H{
K*7*`6iU
private void processErrorCode(int nErrorCode) |os2@G$
{ ~AjbF(Ad
System.err.println("Error Code : " + nErrorCode); @#*B|lHE
} Y49kq}
?#,\,
XLEA|#
//停止文件下载 wUh'1D<(r
public void siteStop() ;#~rd8Z52
{ SY>N-fW\H:
bStop = true; q^"P_pV\
for(int i=0;i<nStartPos.length;i++) 57K1e~^
fileSplitterFetch.splitterStop(); *`|.:'
@<>](4D
~qFi0<-M
} `9zP{p
} IB(IiF5
//负责部分文件的抓取 5IVASqYp
**FileSplitterFetch.java dkG-Yz~
*/ kIU"-;5tP
package NetFox; i]8zZRe
6l:CDPhR
J[VQ6fD%
import java.io.*; T(J&v|FK
import java.net.*; Bi?.G7>
F'pD_d9]e
.6e5w1r63
public class FileSplitterFetch extends Thread { R0oP##]
AL H^tV?
k3S**&i!CR
String sURL; //File URL \-V
long nStartPos; //File Snippet Start Position >"zSW?
long nEndPos; //File Snippet End Position XImb"7|
int nThreadID; //Thread's ID 4;w_o9o
boolean bDownOver = false; //Downing is over zLf^O%zN
boolean bStop = false; //Stop identical gmJJ(}HVz
FileAccessI fileAccessI = null; //File Access interface 9.vHnMcq
L|!9%X0.
R^%7|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (Q#A Br8
{ D$#=;H ,
this.sURL = sURL; h7gH4L!'u
this.nStartPos = nStart; L.+5`&
this.nEndPos = nEnd; @-!w,$F)%d
nThreadID = id; QVzLf+R~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 JK[7&C-O
} m(*CuM[E
F =d L#@^
ywi Shvi8
public void run() (nvSB}?
{ }v=q6C#Q>
while(nStartPos < nEndPos && !bStop) |`:Uww+3
{ XXxX;xz$
oBAD4qK
{#>@h7
try{ '3%!Gi!g
URL url = new URL(sURL); LB2 2doW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,+zLFQC0@
httpConnection.setRequestProperty("User-Agent","NetFox"); 8M(N
String sProperty = "bytes="+nStartPos+"-"; NpH)K:$#%
httpConnection.setRequestProperty("RANGE",sProperty); )Bd+jli|s
Utility.log(sProperty); Wc-P= J*m
F?5kl/("
1wGd5>GDA
InputStream input = httpConnection.getInputStream(); .`xcR]PQ
//logResponseHead(httpConnection); 64b9.5Bn
#l8CUg~Uj
Ww)qBsi8
byte[] b = new byte[1024]; pS0-<-\R
int nRead; KWN0$*4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @36^4E>h
{ G8akMd]2
nStartPos += fileAccessI.write(b,0,nRead); cZ^$!0
//if(nThreadID == 1) {7B$%G'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZaXK=%z
} 7m@pdq5Ub
iK=H9j
8oN4!#:
Utility.log("Thread " + nThreadID + " is over!"); <f{m=Dc
bDownOver = true; Xo{Ce%L
//nPos = fileAccessI.write (b,0,nRead); z\fD}`^8
} dtm_~r7~
catch(Exception e){e.printStackTrace ();} AB}Qd\
} 1sn!!
} 1cOp"!
`=%[
\!z=x#!O$
//打印回应的头信息 HHa7Kh|-H
public void logResponseHead(HttpURLConnection con) j!m~ :D
{ .R biF
for(int i=1;;i++) 1pO ;aG1O
{ 0#sk]Qz
String header=con.getHeaderFieldKey(i); I2K52A+
if(header!=null) J>XaQfzwU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); M}/%t1^g:
Utility.log(header+" : "+con.getHeaderField(header)); YM+}Mmu
else jwAO{.}T1r
break; zXUE<\
} {TE0
} uTB;Bva
sks_>BM
D95$
public void splitterStop() A 7DdUNR
{ ^D oJ='&
bStop = true; S,Zjol%p
} $@8\9Y {
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,ulNap"R
} J,m.LpY
bis/Nfr]
69yTGUG3
/* Ob0=ZW`+&
**FileAccess.java n'4D;4
*//文件访问(定位，写) jCKRoao
package NetFox; glk I9~
import java.io.*; Ldir'FW
Z4hP
fVR ~PG0
public class FileAccessI implements Serializable{ )-9|3`
NF&\<2kX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Dtd bQF
RandomAccessFile oSavedFile; K"-N:OV
long nPos; ?:n{GK
`Rj i=k>
/:awPYGH<1
public FileAccessI() throws IOException \Xxx5:qM
{ hw~cS7
this("",0); r\=p.cw<
} >]C;sP
F)DL/';
9Cf^Q3)5o
public FileAccessI(String sName,long nPos) throws IOException Kau*e8
{ ;;l(
oSavedFile = new RandomAccessFile(sName,"rw"); rw+0<r3|K
this.nPos = nPos; T("Fh}
oSavedFile.seek(nPos); V!FzVl=G
} &Lq @af#
QW6k!ms$
8yztVdh
public synchronized int write(byte[] b,int nStart,int nLen) s/ZOA[Yux
{ Y>%A*|U%
int n = -1; rRC3^X`u
try{ $RA"NIZ:!
oSavedFile.write(b,nStart,nLen); {-17;M$
n = nLen; g08=D$P
} ;?n*w+6<
catch(IOException e) Iun!rv
{ \N"K^kR4
e.printStackTrace (); vO4 &ZQ>6
} D4o?
If4YqBG
!L3Bvb;Q
return n; ZU "y<
} Y`(I};MO
L{gFk{@W
{v]>sn;P1
} [$H8?J
Ud{-H_m+
'u696ED4
/* Bwll [=_I
**SiteInfoBean.java (G$m}ng
*/ 4&t6
package NetFox; x!"!oJG^k
m41n5T`
:;??!V
public class SiteInfoBean { Bq:@ [pCQ
lfI[r|
0/] @#G2
private String sSiteURL; //Site's URL 8E0Rg/DnT
private String sFilePath; //Saved File's Path 3:=XU9p)x
private String sFileName; //Saved File's Name rxDule3m
private int nSplitter; //Count of Splited Downloading File @H{$,\\
Wm3H6o*
G_AAE#r`
public SiteInfoBean() $B$=,^)3
{//nSplitter的缺省值为5 w"l8M0$m
//default value of nSplitter is 5 z*9/"M
this("","","",5); E+7S:B
} 4AF"+L
n+!.0d}6
~i &K,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) wkd591d*
{ uHf~KYL
sSiteURL= sURL; Ap97Zcw
sFilePath = sPath; Y[x ^59
sFileName = sName; sO(Kpo9jq
this.nSplitter = nSpiltter; JL(*peeu3
ec]ksw6T+
o[cKh7&+
} 7q67_u?@
\8t g7Sdq
gE$dz#t.
public String getSSiteURL() <o]tW4\(R
{ qc`_&!*D
return sSiteURL; k| jCc
} r/{VL3}F_e
Jk1Up2#B
(p2\H>pTr
public void setSSiteURL(String value) 2{#quXN9
{ _nTjCN625
sSiteURL = value; iSsy_ |
} n1cAI|ZE
uvmNQg
S$$:G$j
public String getSFilePath() $*@mxwMQ}
{ sJ0y3)PQ
return sFilePath; >ZNL pJQ
} D(r|sw
goHr#@
Y.hrU*[J0
public void setSFilePath(String value) Vy5Q+gw
{ n"MFC
sFilePath = value; 0`S!+d
} p@Qzg /X
<4!w2vxG
Y@r#:BH)
public String getSFileName() TvQAy/Y0
{ [6-l6W
return sFileName; VK NCK
} x[>A'.m@)
g^]Q*EBa
q,*IR*B:a
public void setSFileName(String value) Ne#nSx5,
{ G;^iwxzhO
sFileName = value; o?%x!m>
} Z4(2&t^
P!vBS"S
~ib#x~Db
public int getNSplitter() 6}|vfw
{ $OUa3!U_!
return nSplitter; %`}Qkb/Lyh
} rVN|OLh
NuP@eeF>,
;=n7 Z
public void setNSplitter(int nCount) HML6<U-eS
{ wo_FM `@
nSplitter = nCount; %V+,#
} ^Krkf4fO
} ^%<v| Y(X
X0U6:
)pvZM?
/* 2.NzB7c*CM
**Utility.java i\<l&W
*/ i/$lOde
package NetFox; p,4z;.s$
MDB}G '
l s_i)X
public class Utility { OE[/sv
'@W72ML.
KS|$_-7u
public Utility() ]ny(l#Hu:
{ vx ,yz+yP
$rlIJwqn
?(|!VLu
} !BY=HFT
J[B8sa
//线程睡眠 My[L3KTTp
public static void sleep(int nSecond) 59ivL6=3
{ F0|T%!FB>%
try{ xp39TiXJ*
Thread.sleep(nSecond); V]<dh|x
} w5[POo' 5
catch(Exception e) j[z\p~^
{ %_z]iz4
e.printStackTrace (); 7'o?'He-.2
} Y#Z&$&n
} \l[5U3{
;WzT"yW)T
//日志 'shOSB
public static void log(String sMsg) ]xS< \{og
{ SZ0Zi\W
System.err.println(sMsg); 7O{\^Jz1
} lz>5bR'
\twlHj4
MKH7d/x
public static void log(int sMsg) Jsw<,uTD
{ *$s)p>
System.err.println(sMsg); Zc"]Cv(
} !^N/n5eoz
} ZNx{7]=a
g3qtWS
57oY]NT?
/* =DqGm]tA
**TestMethod.java T@z$g
*/ s_kI\w4(x1
package NetFox; xWlB!r<}Gz
qD9B[s8
kg-%:;y.
public class TestMethod { q|j;dI&
6\]-J*e>
NeWssSje
public TestMethod() 4RzG3CJdS
{ ///xx/weblogic60b2_win.exe k"n#4o:
try{ 7kb`o y;(^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); fG.w;Aemv5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ``O\'{o&
SiteFileFetch fileFetch = new SiteFileFetch(bean); HPgMVp'
fileFetch.start(); ~L1N1Z)Kk
} <fyv^e
catch(Exception e){e.printStackTrace ();} A#p@`|H#B
9\"~G)
:b ;5O3:B
} f.u{;W
!KF;Z|_(I
&"CS1P|
public static void main(String[] args) *yJb4uALB
{ [Z[)hUXE?
new TestMethod(); %ZxKN;
} H37Z\xS
} 3C[;2
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