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)); >*CK@"o
} L@GD$F=<0
for(int i=0;i<nEndPos.length-1;i++) ^2@~AD`&h
{ (Ad!hyE(
nEndPos = nStartPos[i+1]; l]&)an
} 1ki"UF/
nEndPos[nEndPos.length-1] = nFileLength; x*V<afLY[
} @U5>w\
} NDGBvb
)Cfrqe1^
E+ 20->
//启动子线程 rNp#5[e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Xpwom'
for(int i=0;i<nStartPos.length;i++) Gjr2]t;E
{ 2wvDC@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (P8oXb+%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &i RX-)^u
nStartPos,nEndPos,i); r U5'hK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t,nB`g?
fileSplitterFetch.start(); D3ad2vH
} gp2)35
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JnJz{(c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); KYN{iaj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }FVX5/.'
nEndPos = " + nFileLength); ObzlZP r@
// fileSplitterFetch[nPos.length-1].start(); ry"zec B
(7,Awf5D~
wYG0*!Vj
//等待子线程结束 ?Pc3*.
//int count = 0; p7er04/}\
//是否结束while循环 BZ9iy~
boolean breakWhile = false; Bs}>#I
Q8i6kf!
w.H+$=aK
while(!bStop) ?C3cPt"
{ lX3h'h
write_nPos(); |e>-v
Utility.sleep(500); pM3BBF%
breakWhile = true; 6Tnzg`0I
9v0|lS!-
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for(int i=0;i<nStartPos.length;i++) jfamuu7
{ B?Skw{&
if(!fileSplitterFetch.bDownOver) ;0'v`ob'.?
{ FO$Tn+\6
breakWhile = false; UepBXt3)
break; OFv} jT
} Q2Rj0E`
} w3D_ c~
if(breakWhile) K-3 _4As
break; $EF@x}h:A
!4:,,!T
d9"4m>ymS
//count++; $}fA;BP
//if(count>4) ev $eM
// siteStop(); 4aC#Cv:0
} u7d]%<~'$F
{,=,0NQKn
`>Cx!sYhV
System.err.println("文件下载结束！"); E12k1gC`
} KJ_R@,v\
catch(Exception e){e.printStackTrace ();} 8n?.w:Y/
} tw66XxE
>.|gmo>b
~A/_\-
//获得文件长度 LNkyV*TI
public long getFileSize() 3 6 ;hg#
{ {W]jVh p
int nFileLength = -1; xFZq6si?
try{ Rd)QVEk>SD
URL url = new URL(siteInfoBean.getSSiteURL()); wG O)!u 4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c3##:"wr
httpConnection.setRequestProperty("User-Agent","NetFox"); S J5kA`
{Y Ymt!Ic
+zsya4r
int responseCode=httpConnection.getResponseCode(); 'Nh^SbD+_|
if(responseCode>=400) bd4q/w4q
{ `Nj|}^A
processErrorCode(responseCode); )T?ryp3ev
return -2; //-2 represent access is error lS^0*(Y
} @zbXG_J
s><co]
00i9yC8@6
String sHeader; N2>JG]G
Xc!w y9m
;/@R{G{+~;
for(int i=1;;i++) W=!f
{ rAKdf??
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4%TC2Laii
//Utility.log(in.readLine()); (P?9Jct
sHeader=httpConnection.getHeaderFieldKey(i); T (qu~}
if(sHeader!=null) -g0>>{M'
{ Z>l>@wNm
if(sHeader.equals("Content-Length")) 4rm/+Zes
{ cu-WY8n
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ty=}A MMyE
break; E_K7.c4M
} gA6C(##0
} . fIodk
else H|Ems}b
break; a|.u;
} )-(NL!?`
} {Fj`'0Xu;
catch(IOException e){e.printStackTrace ();} G;e}z&6<k
catch(Exception e){e.printStackTrace ();} 5j]%@]M$Z
_bX)fnUu
KjadX&JD
Utility.log(nFileLength); c\Dv3bF
iaB5t<t1r
t`Sh!e
return nFileLength; _3hEYeh
} EO5Vg
<\5{R@A*6
tVOx
//保存下载信息（文件指针位置） $[Fk>d
private void write_nPos() 5M*p1^ >
{ 4:.M*Dz
try{ /SiQw7yp%
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^N]*Zf~N?
output.writeInt(nStartPos.length); {'1,JwSmb
for(int i=0;i<nStartPos.length;i++) <6@Db$-
{ $Ix^Rm9c
// output.writeLong(nPos); %^S1 fUwT
output.writeLong(fileSplitterFetch.nStartPos); zSu2B6YU}
output.writeLong(fileSplitterFetch.nEndPos); 'Gk|&^
} D<MtLwH
output.close(); &b_duWs
} n3(HA
catch(IOException e){e.printStackTrace ();} &\LbajP:+
catch(Exception e){e.printStackTrace ();} tm$3ZzP4
} B4hR3%
0^+W"O
ZM"t.
//读取保存的下载信息（文件指针位置） OHU(?TBo
private void read_nPos() >a<;)K^1
{ >(3y(1;
try{ -8]$a6`{_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .FeEK(
int nCount = input.readInt(); W+QI D/
nStartPos = new long[nCount]; R&?p^!`%
nEndPos = new long[nCount]; fA8 ,wy|>
for(int i=0;i<nStartPos.length;i++) ?g 3sv5\u
{ COap*
nStartPos = input.readLong(); R#0UwRjeF
nEndPos = input.readLong(); %n^]1R#
} #r\uh\Cy
input.close(); di|l?l^l
} Cd4G&(=
catch(IOException e){e.printStackTrace ();} O_~\$b
catch(Exception e){e.printStackTrace ();} v"`w'+
} -{dwLl_
7*sB"_U2
j9%=^ZoQj
private void processErrorCode(int nErrorCode) {'/8{dS
{ HxjhP(
System.err.println("Error Code : " + nErrorCode); +U[A.^t
} `W5f'RU
m9r X
(UCWSA7oc
//停止文件下载 b<%6aRC\
public void siteStop() #}.db?[Rv
{ dP82bk/e
bStop = true; y&UsSS
for(int i=0;i<nStartPos.length;i++) 1'ZBtX~A
fileSplitterFetch.splitterStop(); &a V`u?'e
TV}H
y@F{pr+dA
} !^y'G0
} 5( 3tPbm{
//负责部分文件的抓取 GE|V^_|i
**FileSplitterFetch.java vV%w#ULxE~
*/ L~\Ir
package NetFox; j sm{|'
2gA6$s7
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import java.io.*; &Mol8=V)
import java.net.*; kxh $R>
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D ,nF0p
public class FileSplitterFetch extends Thread { LVX.stN#p
C&\#{m_1B
$aEL>,X
String sURL; //File URL \]zHM.E1
long nStartPos; //File Snippet Start Position u-D%: lz85
long nEndPos; //File Snippet End Position Zf ;U=]R
int nThreadID; //Thread's ID GujmBb
boolean bDownOver = false; //Downing is over iNcB6,++
boolean bStop = false; //Stop identical 06ZyR@.@v
FileAccessI fileAccessI = null; //File Access interface uT_bA0jK
)Zox;}WK+
H?PaN)_6-+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kIyif7
{ mk}8Cu4
this.sURL = sURL; 1$4dzI()
this.nStartPos = nStart; ->d3FR
this.nEndPos = nEnd; svN&~@l
nThreadID = id; y6fYNB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }5EvBEv-)
} s~3"*,3@
{>9vm!<[*\
q>t#5Z81
public void run() b}WU
{ @u?m4v{
while(nStartPos < nEndPos && !bStop) R,8;GS42
{ +Y-Gp4"
r3'0{Nn+
>HyZ~M
try{ V3 2F
URL url = new URL(sURL); XsEDI?p2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?g}G#j
httpConnection.setRequestProperty("User-Agent","NetFox"); ,VI2dNst\
String sProperty = "bytes="+nStartPos+"-"; 6YNd;,it>p
httpConnection.setRequestProperty("RANGE",sProperty); U&GSMjqg
Utility.log(sProperty); voiWf?X
5y0N }}
f]Xh7m(Gh
InputStream input = httpConnection.getInputStream(); UZz/v#y~
//logResponseHead(httpConnection); 1 Qln|b8<
zt6GJz1q
Kqm2TMO]>V
byte[] b = new byte[1024]; m9 1Gc?c
int nRead; @kd`9Yw
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :>f}rq
{ jBb:)
nStartPos += fileAccessI.write(b,0,nRead); A{MMY{K3
//if(nThreadID == 1) z#m ~}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \(C6|-:GY
} UyENzK<%u
~6DaM!
a[I :^S
Utility.log("Thread " + nThreadID + " is over!"); mb,\wZ
bDownOver = true; vhvFBx0
//nPos = fileAccessI.write (b,0,nRead); }Y:V&4DW
} T,r?% G{XE
catch(Exception e){e.printStackTrace ();} shKTj5s?
} $Y,y~4I
} h/k00hD60
xPCRT*Pd
T\q:
//打印回应的头信息 9eBD)tnw
public void logResponseHead(HttpURLConnection con) >P@g].Q-
{ a5caryZ"z
for(int i=1;;i++) r'8qZJgm
{ gamE^Ee
String header=con.getHeaderFieldKey(i); a`I \19p]
if(header!=null) XlLG/N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0fu*}v"
Utility.log(header+" : "+con.getHeaderField(header)); 8 kvF~d ;
else z9Z4MXl
break; \(_(pcl
} 0Xb,ne 7
} 2ci[L:U
z.lIlp2:
=U'!<w<-
public void splitterStop() 9k/L m
{ z;DNl#|!L
bStop = true; C cPOK2
} 9:R3+,ZN
A*G ~#v^
,<k%'a!B
} 6%it`A8}
:CLWmMC_
M0yv=g
/* w p\-LO~
**FileAccess.java Qp7h|<
*//文件访问(定位，写) 1J([*)
package NetFox; =WT&unw}
import java.io.*; o%7-<\qS
fqjBor}
;.'?(iEB
public class FileAccessI implements Serializable{ ulE5lG0c
X!_&%^L'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e>6|# d
RandomAccessFile oSavedFile; @Bds0t
long nPos; {7jl) x3l
X$e*s\4
!0dQfj^_
public FileAccessI() throws IOException i-PK59VZ8f
{ p4V*%A&w
this("",0); |sdG<+
} tk]D)+{u&c
i\<S ;
k4a51[SYBK
public FileAccessI(String sName,long nPos) throws IOException _3(rwD
{ !wN2BCSY@
oSavedFile = new RandomAccessFile(sName,"rw"); 3\2%i6W6
this.nPos = nPos; )r^vrCNy>
oSavedFile.seek(nPos); BmKf%:l}
} @^T~W^+
p#).;\M
rY6x):sC
public synchronized int write(byte[] b,int nStart,int nLen) KLvAe>#,
{ p[w! SR%=
int n = -1; LN~mKoW
try{ ]DKRug5
oSavedFile.write(b,nStart,nLen); Q 9fK)j1$
n = nLen; EB| iW2'
} dP?prT
catch(IOException e) M!+J[q
{ ?z`={oN
e.printStackTrace (); oUwo!n}
} 3CgID6[Sy
<o/!M6^:
b{qN7X~>
return n; SV@*[r
} ~P#mvQE)
0N^+d,Xt.
ltfKqY-
} <3!Al,!ej@
$2\8Rn6'
yUj`vu2
/* o3V\
**SiteInfoBean.java (P`=9+
*/ :h5G|^
package NetFox; $m;`O_-T
y{/7z}d
0KnL{Cj
public class SiteInfoBean { ?HJh;96B
j*@@H6G
jB8Q% {%
private String sSiteURL; //Site's URL ele@xl
private String sFilePath; //Saved File's Path ;Ax-f04gG
private String sFileName; //Saved File's Name \o}T0YX
private int nSplitter; //Count of Splited Downloading File Asv]2> x
XHekz6_
sEFQ8S
public SiteInfoBean() @QV0l]H0+
{//nSplitter的缺省值为5 *#'j0;2F
//default value of nSplitter is 5 H.\`(`6
this("","","",5); T[ZmD{6l
} \?; `_E`j
ss[`*89
wn.~Dx
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) n74\{`8]o
{ y92R}e\M
sSiteURL= sURL; +9w[/n^,G
sFilePath = sPath; Iz1x|EQ
sFileName = sName; [a04( 2g
this.nSplitter = nSpiltter; `p&[b]b
>*RU:X
<mQXS87
} LP6p
l3sF/zkH
|]4!WBK
public String getSSiteURL() T[Zs{S
{ HwHF8#D*l
return sSiteURL; c`soVqT$?
} '|DW#l\n
-T,?'J0 2
Up{[baWF
public void setSSiteURL(String value) :D*U4< /u
{ =..Bh8P71!
sSiteURL = value; aOH|[
} ^K;k4oK
sFc\L94
. :Skc
public String getSFilePath() j:h}ka/!p
{ sq!$+=1-X
return sFilePath; mY.v:
} 1Z)Et,
8cG?p
G IN|cv=
public void setSFilePath(String value) #B;P4n3
{ c,4~zN8Ou
sFilePath = value; -g@!\{
} m<h%BDSzr{
/?eVWCR
g}s$s}
public String getSFileName() Y~AjcqS
{ )O]6dd
return sFileName; '{"Rjv7
} QselW]
j|t=%*
3[ xdls
public void setSFileName(String value) ECOJ .^
{ ~Q&J\'GQH
sFileName = value; HU'Mi8xxy
} ob\-OMNs@
hx9{?3#
--WQr]U/
public int getNSplitter() V`y^m@U!
{ VHxBs
return nSplitter; ( zWBrCX
} <0})%V?-
X:oOp=y]|
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public void setNSplitter(int nCount) krUtOVI
{ Vh^y6U<
nSplitter = nCount; ^ Oh
} k7^hcth
} \rS*\g:i
4j#y?^s
(xHmucmwp
/* J].Oxch&y
**Utility.java $-}&RW9
*/ %T({;/
package NetFox; Sc7 Ftb%
>Uw:cq
)0VL$A
public class Utility { 'z ?Hv
x4WCAqi/2
cUY-
public Utility() geme_
{ eFG/!b<17
3`bQ0-D;
;P91'B~t
} {7o3wxsS
6KMO*v
//线程睡眠 |J-X3`^\H
public static void sleep(int nSecond) [E1qv;
{ #EH=tJgO|J
try{ "`>6M&`U
Thread.sleep(nSecond); 0P$1=oK
} 8A#,*@V[
catch(Exception e) ~CNB3r5R
{ MgXZN{
e.printStackTrace (); Tn&_ >R
} csy6_q(
} MTu\T
Sq5,}oT_{j
//日志 \Y4(+t=4
public static void log(String sMsg) B[N]=V
{ TTXF r
System.err.println(sMsg); w?ugZYwX*
} NM{)liP ;8
_4by3?<c
J :O!4gI
public static void log(int sMsg) cYA:k
{ e$[O J<t
System.err.println(sMsg); ZC?~RXL(
} wW%b~JX
} $|~<6A{y
uj8saNu
287j,'vR
/* ^B<-.(F
**TestMethod.java 4fi4F1f
*/ /HdXJL9B
package NetFox; 1dN/H)]
V'kBF2}
dla_uXtM6
public class TestMethod { 1CC0]pyHX
?(9*@
=t,oj6P~
public TestMethod() hIV9.{J
{ ///xx/weblogic60b2_win.exe LeCc`x,5
try{ _}F&^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "S;4hO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j9fBl:Fr
SiteFileFetch fileFetch = new SiteFileFetch(bean); !]F`qS>
fileFetch.start(); o@)Fy51DD
} Ue}1(2.v
catch(Exception e){e.printStackTrace ();} 1S?~c25=h
j,OA>{-$
d]E=w6+;Q
} .\oz
Ic'D#m
G#%Sokkb'
public static void main(String[] args) & DP"RWT/
{ OeQ[-e
new TestMethod(); wq?"NQ?O<
} iHv+I~/
} F@<cp ?dR
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