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)); I uC7Hx`z
} cR=o!2O
for(int i=0;i<nEndPos.length-1;i++) tZY6{,K%4
{ ;YZ'd"0v
nEndPos = nStartPos[i+1]; C^fn[plL
} d[YG&.}+8j
nEndPos[nEndPos.length-1] = nFileLength; P @~)9W
} ]2c0?f*Y7
} N<O<wtXIj
iB}*<~`.Eg
RBLOc$2
//启动子线程 [ut[W9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; txiX1o!/L
for(int i=0;i<nStartPos.length;i++) 3TRG] 5
{ &Z(6i}f,Gp
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t[/APm-k~>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :eH\9$F`x;
nStartPos,nEndPos,i); YH&q5W,KX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !ou;yE&<,
fileSplitterFetch.start(); tHEZuoi
} (W.G&VSn)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4N5\sdi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /@1pm/>ZaN
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Fd#Zu.Np
nEndPos = " + nFileLength); VV/aec8
// fileSplitterFetch[nPos.length-1].start(); 4+Jf!ovS=
1/v#Z#3[
V0G[f}tm'
//等待子线程结束 3pe1"maP
//int count = 0; p/HGI)'
//是否结束while循环 3U'l'H,
boolean breakWhile = false; iikMz|:7U
30O7u3Zrb
*6G@8TIh
while(!bStop) "|BSGV!8
{ Hb[P|pPT
write_nPos(); T_d)1m fl
Utility.sleep(500); }/4),W@<
breakWhile = true; Q)=2%X
x2f=o|]D'
,'n`]@0?\
for(int i=0;i<nStartPos.length;i++) >2ha6A[
{ 2|&SG3e+(I
if(!fileSplitterFetch.bDownOver) MS]Q\g}U
{ 6(>,qt,9S
breakWhile = false; Fd<eh(g9P
break; JL[!8NyU
} [{: l?
} *;F:6p4_
if(breakWhile) Yq'D-$@
break; <O.|pJus
SX&Q5:
K'y|_XsBB)
//count++; CaVVlL
//if(count>4) %LuA:{EVD
// siteStop(); M^lP`=sSv
} 6`X}Z'4.Ox
i v.G
:x3xeVtY
System.err.println("文件下载结束！"); i0Rj;E=:]
} $&&+2?cx0
catch(Exception e){e.printStackTrace ();} <*9(m
} bwa*|{R
>uDC!0)R
bq9/d4
//获得文件长度 OuKRaZ
public long getFileSize() xz~Y %Y|Z
{ av_ +M;G
int nFileLength = -1; Z@bSkO<Y
try{ vpC?JXz=H
URL url = new URL(siteInfoBean.getSSiteURL()); y8Rq2jI;(e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); csA-<}S5]b
httpConnection.setRequestProperty("User-Agent","NetFox"); @1i<=r
Ro;I%j
mW~*GD~r
int responseCode=httpConnection.getResponseCode(); s~ou$!|
if(responseCode>=400) 6 $`l
{ .@ZrmO o]]
processErrorCode(responseCode); sLWVgD
return -2; //-2 represent access is error HA[7)T N1E
} < FY%QB)h
[,{Nu EI
";/ogFi
String sHeader; )i_:[ l6
D G|v'#
IyM:9=}5
for(int i=1;;i++) z|t2;j[
{ 8m?cvI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /<%EKu5
//Utility.log(in.readLine()); 'rq@9$h1W
sHeader=httpConnection.getHeaderFieldKey(i); !,C8
if(sHeader!=null) xdVsbW)L2
{ xo2jfz
if(sHeader.equals("Content-Length")) i5|)|x3
{ :i|]iXEI"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); y(#6nG@S
break; o' v!83$L
} c^&4m[?C[u
} aMVq%{U
else ZUvc|5]
break; 7fXJP5j
} )1YX+',"
} 2.\"Q
catch(IOException e){e.printStackTrace ();} Y/?z8g'p
catch(Exception e){e.printStackTrace ();} LXZI|K[}k
0g~Cdp
3E0C$vKM
Utility.log(nFileLength); Z{/GT7 /
8n:N#4Dh^
0JKTwLhC
return nFileLength; 5m;BL+>YE
} GDb Vy)&
6G}4KGQc
73nM9
//保存下载信息（文件指针位置） `sgW0Uf
private void write_nPos() nwzyL`kF
{ ))nTd=
try{ Cs\jPh;"
output = new DataOutputStream(new FileOutputStream(tmpFile)); dpX Fx"4A
output.writeInt(nStartPos.length); ru~!;xT
for(int i=0;i<nStartPos.length;i++) bAy\Sr #/
{ H/Rzs$pnv
// output.writeLong(nPos); z:
output.writeLong(fileSplitterFetch.nStartPos); OmK4 \_.
output.writeLong(fileSplitterFetch.nEndPos); _'<FBlIN
} e{3%-
output.close(); vF&0I2T~l
} B79~-,Yh
catch(IOException e){e.printStackTrace ();} KXpbee
catch(Exception e){e.printStackTrace ();} o,S(;6pDJ
} %$'fq*8b
0F.S[!I
a7=lZZ?
//读取保存的下载信息（文件指针位置） !6z{~Z:
private void read_nPos() B@#vS=g
{ N1.fV-
try{ >;R7r|^k
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); NjPQT9&3h
int nCount = input.readInt(); AX Q.E$1g
nStartPos = new long[nCount]; I*$-[3/
nEndPos = new long[nCount]; d+6q%U
for(int i=0;i<nStartPos.length;i++) PHUeN]s#
{ e}P@7e h
nStartPos = input.readLong(); A;*<
nEndPos = input.readLong(); ~Nf|,{[(5
} Mz+vT0
input.close(); 2+b}FVOe\
} >>"@0tO
catch(IOException e){e.printStackTrace ();} ggm'9|
catch(Exception e){e.printStackTrace ();} >yVp1Se
} lR9uD9Dr
n,LM"N:
B=7maYeU
private void processErrorCode(int nErrorCode) cV_-Bcb
{ wAJ=rRI
System.err.println("Error Code : " + nErrorCode); )]4=anJu@|
} u^#e7u
ZHlHnUo
~B?Wg!
//停止文件下载 d @ l
public void siteStop() .:GOKyr(~
{ wp5H|ctl
bStop = true; dV16'
for(int i=0;i<nStartPos.length;i++) .p?SPR
fileSplitterFetch.splitterStop(); qQ6@43TC
-yTIv*y
,oPxt
} ledr[)
} |`s:&<W+kp
//负责部分文件的抓取 N R4\TU
**FileSplitterFetch.java Aon.Y Z
*/ CS5[E-%}T=
package NetFox; -WR<tkK
2;J\Z=7
6V}xgfB
import java.io.*; EJQT\c
import java.net.*; SJlE!MK
+_u~Np
[hk/Rp7{
public class FileSplitterFetch extends Thread { %Pj}
~*UY[!+4^=
7,8TMd1`M
String sURL; //File URL 8?x:PkK
long nStartPos; //File Snippet Start Position pYu6[
long nEndPos; //File Snippet End Position tmM; Z(9t
int nThreadID; //Thread's ID Y>ATL
boolean bDownOver = false; //Downing is over 3-)}.8F
boolean bStop = false; //Stop identical uPxjW"M+
FileAccessI fileAccessI = null; //File Access interface g5u4|+70
LafBf6wds
12_7UWZ"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8G9( )UF.
{ %+<1X?;,Fq
this.sURL = sURL; #};Zgixo$
this.nStartPos = nStart; };EB[n
this.nEndPos = nEnd; jW-;Y/S
nThreadID = id; 412E7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hE$3l+
} |JP'j1 Ka
fny6`_O
M)AvcZNs
public void run() h@\HPYi#.
{ b!`Ze~V
while(nStartPos < nEndPos && !bStop) U~t!
{ ,?Zy4-
53pT{2]zAi
s.n:;8RibP
try{ Q<ia
URL url = new URL(sURL); E*fa&G~s )
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Kp1 F"!
httpConnection.setRequestProperty("User-Agent","NetFox"); q^n LC6q
String sProperty = "bytes="+nStartPos+"-"; ;Ru[^p.{
httpConnection.setRequestProperty("RANGE",sProperty); Q&_#R(3j;
Utility.log(sProperty); >l/pwb@
6A}tA$*s7
JnIG;/
InputStream input = httpConnection.getInputStream(); inZ0iU9dy
//logResponseHead(httpConnection); moh,aB#
Kv<mDA!
Y6d~hLC
byte[] b = new byte[1024]; v\qyDZVV
int nRead; $#3[Z;\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m_BpY9c]5
{ 7Kb&BF|Q
nStartPos += fileAccessI.write(b,0,nRead); C8)Paop$
//if(nThreadID == 1) Aayd3Ph0%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1$6 u
} >!{8)ti
w^YXnLLJG
6E:H
Utility.log("Thread " + nThreadID + " is over!"); F:[[@~z
bDownOver = true; qt/6o|V
//nPos = fileAccessI.write (b,0,nRead); Y9vVi]4
} p9mGiK4!
catch(Exception e){e.printStackTrace ();} NYs<`6P:Y
} [KbLEMrPba
} jO|`aUYTf
RL/7>YQ
l @@pXg3
//打印回应的头信息 |TkicgeS
public void logResponseHead(HttpURLConnection con) PxvxZJf$@
{ aG4 ^xOD
for(int i=1;;i++) <w8H[y"c
{ I,,SR"
String header=con.getHeaderFieldKey(i); z7)$m0',?
if(header!=null) /h`gQyGuY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Eb63O
Utility.log(header+" : "+con.getHeaderField(header)); 1&7?f
else 7^UY%t
break; >9#) obw
} Zy:q)'D=
} :eB+t`M
0Q,Tcj
0b8=94a{>
public void splitterStop() *ezft&{)`
{ >TawJ"q-6R
bStop = true; qD=b+\F
} P6ka'!z
NiE`u m
T?.l_"%%d
} ZC<EPUV(
}j2t8B^&:
XtBEVqrhi
/* D(dV{^} 9
**FileAccess.java `_ZbA#R,
*//文件访问(定位，写) sE|8a
package NetFox; `022gHYv
import java.io.*; (dO0`wfM
p<l+js(5|
)-}<}< oO
public class FileAccessI implements Serializable{ +2Aggv>*
n:s _2h(u
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?>vkY^/
RandomAccessFile oSavedFile; *p0n^XZ% ?
long nPos; ~YviXSW
c*"P+
7X>@r"9<
public FileAccessI() throws IOException mYXL
{ BrzTOkeyG
this("",0); $`t2SD
} h2:TbQ
fmUrwI1 %
PG|Zu3[
public FileAccessI(String sName,long nPos) throws IOException -JFW ,8=8
{ F4Cq85#
oSavedFile = new RandomAccessFile(sName,"rw"); M.)z;[3O
this.nPos = nPos; +G7[(Wz(z
oSavedFile.seek(nPos); ,5 3`t
} I!K-* AB
n>SK2`
HoWK#Nz\
public synchronized int write(byte[] b,int nStart,int nLen) {%,4P_m
{ 4wa3$Pk
int n = -1; Cyg(~7]
try{ puEu)m^
oSavedFile.write(b,nStart,nLen); "l#"c{ee{
n = nLen; XZ8]se"C
} 3qV\XC+
catch(IOException e) -ntQqHs
{ ]}]+aB
e.printStackTrace (); ke/4l?zs
} kKC] n
M$6;&T
7v.O Lp
return n; $V/Ke
} ; =*=P8&5
U2Ky4UFm
c+whpQ=01
} nKTi"2dm
v&f\ Jv7
7 VYhRC-
/* AkO-PL
**SiteInfoBean.java eV;nTj
*/ 9u3P>a~b
package NetFox; u:wijkx
bIV9cpW
F hyY+{%
public class SiteInfoBean { KyqP@ {
7WmY:g#s
s]D1s%Mx
private String sSiteURL; //Site's URL k6\&[BQs
private String sFilePath; //Saved File's Path {?3i^Q=V
private String sFileName; //Saved File's Name V*@&<x"E
private int nSplitter; //Count of Splited Downloading File : 'pK
7p{uRSE4._
XuU>.T$]c
public SiteInfoBean() D@@"w+
{//nSplitter的缺省值为5 ~BnmAv$m[
//default value of nSplitter is 5 X|R"8cJ
this("","","",5); scrss
} JX{rum
)"E1/$*k
zYftgH_o
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) FIQHs"#T
{ !4YmaijeN
sSiteURL= sURL; DKl\N~{F
sFilePath = sPath; :"Rx$;a
sFileName = sName; "|PX5
this.nSplitter = nSpiltter; K_qA[n
&nY#GHB
)31xl6@
} ;iUO1t)^
=%b1EYk
~P*{%=a
public String getSSiteURL() }|znQ3A2\l
{ 1XHE:0!dQ
return sSiteURL; bhfC2@
} b$`/f:_
DYgz;Y/%l
+9#qNkP
public void setSSiteURL(String value) J d,9<m$
{ >h(GmR*xM
sSiteURL = value; ]tmMk7
} 7<X!Xok
5BM6Pnle
J{nA ?[
public String getSFilePath() Q>L.
{ ._&SS,I5VZ
return sFilePath; hF5(1s}e$
} U8<C4
`9|Uu#x
qGP}
public void setSFilePath(String value) Mh@n>+IR
{ p.x2R,CU
sFilePath = value; -NA2+].
} +Y>oNX1KN
UM^~a$t
Cli:;yi&n
public String getSFileName() qga?-oz,<6
{ R|_._Btu!
return sFileName; r,P`$-
} A}_pJH
pxW*kS
R pT7Nr
public void setSFileName(String value) ao@CPB6N
{ | S'mF6Y
sFileName = value; qtFHA+bO
} g3(LDqB'.
EWOa2^%}Z\
vXG?8Q
public int getNSplitter() Xu|2@?l9
{ *dsI>4%m
return nSplitter; XaMsIyhI
} SUjo%3R
(?"z!dgc
3kVN[0
public void setNSplitter(int nCount) c Ze59
{ `X<a(5[vV3
nSplitter = nCount; F#.ph?W
} r^ABu_u(`I
} (]zi;
]oC"gWDYu
<*oV-A
/* @\W-=YKLg
**Utility.java >oC{YYcK
*/ q)J5tBfJ
package NetFox; QuC_sFP10
^|2m&2
ZEvK
public class Utility { 32`Z3-
_z9~\N/@[
@3bVjQ`4f
public Utility() n+nZ;GJ5d
{ > }kZXeR|
)UyJ.!Fly
zV(aw~CbZ
} 6;;2e> e
</aQ
//线程睡眠 sd =bw
public static void sleep(int nSecond) }c>vk
{ f>3)}9?xc}
try{ Tr;.O?@{t}
Thread.sleep(nSecond); 8~&=vc
} [a?bv7Kz
catch(Exception e) W_,7hvE?"H
{ 7xYz9r)w`
e.printStackTrace (); 14*6+~38m&
} aIh} j,
} PWkSl
|nGv:= H@
//日志 UT[{NltH
public static void log(String sMsg) ;' H\s
{ u6| IKZ
System.err.println(sMsg); /XU=l0u
} r3KNRr@
~$hR:I1
-=5~-72~
public static void log(int sMsg) .yFO] r1aL
{ RDjw|V
System.err.println(sMsg); b?qV~Dgk`
} bf{_U%`
} [IAk9B.\
>yHtGIHe-
NJVkn~<
/* ^:}C,lIrG
**TestMethod.java 3IB9-wG
*/ _VTpfeL@n
package NetFox; p<}y'7(
K<`W>2"
'J5F+,\Ka
public class TestMethod { 67Qu<9}<-
o?j8"^!7
X.[bgvm~C
public TestMethod() t&q~ya/C
{ ///xx/weblogic60b2_win.exe Wkjp:`(-$r
try{ 0'$67pY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); GN! R<9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q{f\_2[
SiteFileFetch fileFetch = new SiteFileFetch(bean); -)')PV_+
fileFetch.start(); "0#(<zb|
} h4|}BGO
catch(Exception e){e.printStackTrace ();} at@tS>Dv
0D '^:
GWPBP-)0
} JJ_Z{
QkD ~
g@4~,
public static void main(String[] args) wS#Uw_[
{ {4Kvr4)4
new TestMethod(); EC[]L'IL
} :}Yk0*
} 4=|Q2qgFV
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