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)); aoz+Th3
} _<]0hC
for(int i=0;i<nEndPos.length-1;i++) HPu+ 4xQV
{ &~;M16XM,e
nEndPos = nStartPos[i+1]; +-b'+mF
} Wtaz@+
nEndPos[nEndPos.length-1] = nFileLength; #)n$Q^9&
} 8VG}-
} )a0l:jEOc
9{3_2CIL
(gYW iz
//启动子线程 )n"0:"Ou
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2u-J+
for(int i=0;i<nStartPos.length;i++) .h4NG4FIF
{ ,){#J"W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X*MK(aV3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z^Um\f
nStartPos,nEndPos,i); Z796;qk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |X*y-d77W
fileSplitterFetch.start(); VMF?qT3Nd
} ]@21KO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W{Je)N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); phG*It}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F3vywN1$,
nEndPos = " + nFileLength); 0'f\>4B
// fileSplitterFetch[nPos.length-1].start(); OmkJP
+5I5
G11KAq(
//等待子线程结束 a~@f,bw
//int count = 0; w:nH_x#C4
//是否结束while循环 U]+IP;YS
boolean breakWhile = false; L8n?F#q
@r[SqGa:
mW{uChHP
while(!bStop) $,O8SW.O$
{ &\ca ? #
write_nPos(); ]#DCO8Vk
Utility.sleep(500); u(yN81
breakWhile = true; Ohj^Z&j
b00$3,L
EdqB4-#7
for(int i=0;i<nStartPos.length;i++) \:F$7 *Ne
{ fe<7D\Sp@
if(!fileSplitterFetch.bDownOver) Y=|20Y\K
{ 2%fzRXhu%
breakWhile = false; ~tTn7[!
break; s>G]U)d<'
} W;T0_=
} D^h! ].3 T
if(breakWhile) F0&ubspt\
break; WJ-.?
AvZ5?rN$
Zgp9Uu}"
//count++; a_/4^+
//if(count>4) doTbol?+
// siteStop(); &c"!Y)%G
} !4#qaH-Q
]v5/K
)uAY_()/
System.err.println("文件下载结束！"); DazoY&AWE
} X0+E!~X$zM
catch(Exception e){e.printStackTrace ();} XPf{R619
} [?:MIl#!
!_3b#Caf
Z'9|
//获得文件长度 u4T$
public long getFileSize() q9_AL8_
{ C7R3W,
int nFileLength = -1; I6;6x
try{ yKrbGK*=_
URL url = new URL(siteInfoBean.getSSiteURL()); BI%~0Gj8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -1B.A
httpConnection.setRequestProperty("User-Agent","NetFox"); 6ERMn"[_w
#wT6IU1
x&J\swN9
int responseCode=httpConnection.getResponseCode(); KwMt@1Z
if(responseCode>=400) Fhllqh)
{ y@$E5sz
processErrorCode(responseCode); l="X|t
return -2; //-2 represent access is error dHiir&Rd9`
} YCStX)r
GPGPteC
H-&27?s^
String sHeader; T<>B5G~%
]!!?gnPd5
4Zu1G#(zP
for(int i=1;;i++) @i(9k
{ u59l)8=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {R63n
//Utility.log(in.readLine()); ny+r>>3Td
sHeader=httpConnection.getHeaderFieldKey(i); mzM95yQ^Z
if(sHeader!=null) ZZ{c
{ T#!% Uzz
if(sHeader.equals("Content-Length")) U5-8It2OR
{ .]KC*2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f^hJAZ
break; z]hRc8g}d
} <)LR
} Ap?,y?
else JAjiG^]
break; ?kZ-,@h:
} 3mYW]
} `Rq|*:LV
catch(IOException e){e.printStackTrace ();} "XV@OjrE
catch(Exception e){e.printStackTrace ();} Q_fgpjEh/t
6Hb a@Q1`
z__t8yc3
Utility.log(nFileLength); PN9vg9'
E=,b;S-
Oprfp^L
return nFileLength; *szs"mQ/
} SX'NFdY
Ebj0 {ZL
1 Vc_jYO@
//保存下载信息（文件指针位置） ECM#J28D
private void write_nPos() VFF5Tp
{ j+-`P5
try{ 2/t;}pw8
output = new DataOutputStream(new FileOutputStream(tmpFile)); j>\rs|^O
output.writeInt(nStartPos.length); Z@x&
for(int i=0;i<nStartPos.length;i++) cs\=8_5
{ t 3N}):
// output.writeLong(nPos); t@#5 G* _Q
output.writeLong(fileSplitterFetch.nStartPos); (i(E~^O
output.writeLong(fileSplitterFetch.nEndPos); n7~3~i`D;
} t>%b[(a
output.close(); IFr"IOr'l
} mT@Gf>}/A
catch(IOException e){e.printStackTrace ();} 9&zR i
catch(Exception e){e.printStackTrace ();} HH6H4K3Zj
} ^|vk^`S
iJ*Wsp
a]P%Y.?r
//读取保存的下载信息（文件指针位置） <4;, y*"n
private void read_nPos() bp?TO]LH
{ KK>jV
try{ W!.FnM5x
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }oG6XI9
int nCount = input.readInt(); JBw2#ry
nStartPos = new long[nCount]; uA =%EEZ
nEndPos = new long[nCount]; Bx}"X?%S
for(int i=0;i<nStartPos.length;i++) _nzq(m1@
{ ,MJddbcg
nStartPos = input.readLong(); [cEGkz
nEndPos = input.readLong(); 9'~qA(=.?
} 8/)q$zs
input.close(); !F~1+V>zP
} bxxLAWQ(
catch(IOException e){e.printStackTrace ();} \6APU7S
catch(Exception e){e.printStackTrace ();} WhH60/`
} 5"3`ss<m
I+kL;YdS
3l`"(5
private void processErrorCode(int nErrorCode) cy mC?8<
{ .Xf_U.h$*@
System.err.println("Error Code : " + nErrorCode); nXfz@q
} Si~wig2
ljrJC
6=JJ!`"<2
//停止文件下载 Cpd>xXZz&S
public void siteStop() u:(=gj,~x
{ 0^J%&1aIc
bStop = true; 4%qmwt*p
for(int i=0;i<nStartPos.length;i++) X1oR
fileSplitterFetch.splitterStop(); s8]%L4lvu
H@zv-{}T8
(ESFR0
} U)-aecB!
} avG#0AY
//负责部分文件的抓取 \,p?pL<'
**FileSplitterFetch.java )q4nyT>M
*/ >a2[P"
package NetFox; ,*lns.|n
2w1Mf<IXPo
5Y`4%*$
import java.io.*; N`N=}&v ]
import java.net.*; T$r/XAs
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o8E<_rei
public class FileSplitterFetch extends Thread { hB\BFVUSn/
d72 yu3
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String sURL; //File URL hr'?#K
long nStartPos; //File Snippet Start Position Q2)5A&U\
long nEndPos; //File Snippet End Position XZ$g~r
int nThreadID; //Thread's ID Dqwd=$2%
boolean bDownOver = false; //Downing is over '#j6ZC/?
boolean bStop = false; //Stop identical }mZCQJ#`
FileAccessI fileAccessI = null; //File Access interface 6z~ [Ay
3ZSU^v
}*-fh$QJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p*cyW l
{ Mx93D
this.sURL = sURL; r?0w5I
this.nStartPos = nStart; 5B8/"G
this.nEndPos = nEnd; &l{ctP%q
nThreadID = id; leizjL\P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y<`:I|y
} $ <[r3
;*Y+.?>a
5gx;Bp^_
public void run() *)\y52z
{ g0/R\
while(nStartPos < nEndPos && !bStop) x3Fn'+
{ GP^^ K
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%(?;`
try{ vft7-|8T
URL url = new URL(sURL); {ByKTx&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #|:q"l9
httpConnection.setRequestProperty("User-Agent","NetFox"); [!KsAsmk
String sProperty = "bytes="+nStartPos+"-"; *}(B"FSO
httpConnection.setRequestProperty("RANGE",sProperty); r_'];
Utility.log(sProperty); !.@:t`w
4^Ks!S>K{8
TDPQ+Kg_
InputStream input = httpConnection.getInputStream(); G6Wa0Z
//logResponseHead(httpConnection); @wAYhnxq
k-s|gC4
r`)'Kd
byte[] b = new byte[1024]; +\PLUOk
int nRead; OaN"6Ge#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^eRbp?H*T
{ t?weD{O
nStartPos += fileAccessI.write(b,0,nRead); B=_5gZ4Y
//if(nThreadID == 1) e*D,2>o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \Z~@/OVc
} Pa|*Jcr
>K%+h)%kI
4 l+z
Utility.log("Thread " + nThreadID + " is over!"); V%M@zd?u.
bDownOver = true; a{ByU%
//nPos = fileAccessI.write (b,0,nRead); +]H!q W:
} 0H'G./8
catch(Exception e){e.printStackTrace ();} \)MzUOZn
} Esj1Vv#
} ^q}phj3E
b|k(:b-G&.
a[!:`o1U
//打印回应的头信息 V2 ;?
public void logResponseHead(HttpURLConnection con) pnv)D}"
{ ESS1 L$y
for(int i=1;;i++) 8jky-r
{ uAk>VPuuZ
String header=con.getHeaderFieldKey(i); ?6MUyH]a
if(header!=null) 9I1`*0A
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gIGi7x
Utility.log(header+" : "+con.getHeaderField(header)); KAr5>^<zw
else 4>HQ2S{t
break; !Xq5r8]
} AQ"rk9Z
} gd]k3XN$f
-gb@BIV#
iNL>TVUM
public void splitterStop() \/Zo*/
{ &y3;`A7,
bStop = true; q?0&0
} 1yc$b+TH
[A;0IjKam
U:aaa
} [|YuT:Cp
(I1^nrDP.
H,!yG5yF
/* K1-3!G
**FileAccess.java sa"!ckh
*//文件访问(定位，写) @_#]7
package NetFox; qs (L2'7/
import java.io.*; Nfl5tI$U:
Ivq|-LDNc
8feLhWg'P
public class FileAccessI implements Serializable{ /)Weg1b
ZzT"u1,&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ZZeF1y[q
RandomAccessFile oSavedFile; f_.0 uM
long nPos; #Y'ub 5s
BL\H@D
wI[J>9Qn
public FileAccessI() throws IOException 2d OUY $4
{ wFL7JwK:G
this("",0); %LnG^L
} kxY9[#:<fB
( d8rfet
<+<,$jGC-
public FileAccessI(String sName,long nPos) throws IOException v +?'/Q%
{ GRgpy
oSavedFile = new RandomAccessFile(sName,"rw"); 17ynFHMd,
this.nPos = nPos; J>0RN/38o
oSavedFile.seek(nPos); OK:YnSk"
} #]wBXzu?
VQ2B|v
1L_(n
public synchronized int write(byte[] b,int nStart,int nLen) h7}P5z0F
{ X/S%0AwZ
int n = -1; }~ga86:n0
try{ n=h!V$X
oSavedFile.write(b,nStart,nLen); ^QTkre
n = nLen; zgSv -h+f
} `S]DHxS
catch(IOException e) B!1L W4^
{ ","to
e.printStackTrace (); DPlmrN9@=
} _&$nJu
+Jq~39
zj;KtgcE
return n; ,Mu"r!MK
} )dRBI)P
KC-@2,c9V
};~I#X
} YD;"_yH
v<]$,V]
9E
/* | Fk9ME
**SiteInfoBean.java 8ao>]5Rs3
*/ ztaSIMZ
package NetFox; r 4+%9)
-lI6!a^
$w! v
public class SiteInfoBean { t&(\A,ch%
N6/;p]|
wgKM6?
private String sSiteURL; //Site's URL $"{I|UFC
private String sFilePath; //Saved File's Path ^cIRP
private String sFileName; //Saved File's Name @9h6D<?
private int nSplitter; //Count of Splited Downloading File [F^j(qTR
lUM-~
I oC}0C7
public SiteInfoBean() /h K/t;
{//nSplitter的缺省值为5 iaQ3mk#
//default value of nSplitter is 5 2NWQiSz
this("","","",5); ,mD{4 >7
} (fC U+
h_xzqElZu
FmtV[C#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5[rA>g~
{ qa/VSk!{
sSiteURL= sURL; S>EO6z#
sFilePath = sPath; sKL"JA T
sFileName = sName; @D=i|f
this.nSplitter = nSpiltter; Ug^vVc)
bqm%@*fZo
J]$]zD
} C +S>;1
T|h'"3'
Ku]<$uo
public String getSSiteURL() 95BRZ!ts
{ xayd_RB9
return sSiteURL; :@sjOY
} TM`6:5ONv
w?A6S-z
p!p:LSk"/b
public void setSSiteURL(String value) ,Zs*07!$f
{ 4k=LVu]Kcr
sSiteURL = value; 43o!Vr/S
} Gq;!g(
tp3 !6I6
Z oQPvs7_
public String getSFilePath() G:!'hadw
{ :LX (9f
return sFilePath; [|oOP$u
} JCZ5q9b
pq<2:F:Kl
C4t@;U=x
public void setSFilePath(String value) ?H(']3X5@
{ Qon>[<]B
sFilePath = value; :P20g](
} mu&%ph=
[[vbw)u
fk?(mxx"
public String getSFileName() !1ZrS
{ B-EDVMu
return sFileName; Vi\kB%
} ./E<v
u75(\<{
'n4 iW
public void setSFileName(String value) GF^?#Jh
{ >`D$Jz,
sFileName = value; 5TVA1
} jmh$6 N% F
z)]Br1
Id40yER
public int getNSplitter() {,zn#hU.R
{ PitDk 1T
return nSplitter; {qPu}?0
} 9|1J pb
w]Z:Y`
IRB BLXv7\
public void setNSplitter(int nCount) }C9P--
{ Rkz[x
nSplitter = nCount; szU_,.\
} ZH8Oidj`
} x"n)y1y
-4nSiI
J:Ncy}AO
/* s2iL5N|"Q
**Utility.java @}iY(-V
*/ B>,&{ah/5J
package NetFox; ,lr\XhO
EZg$mp1
b0!ZA/YC-
public class Utility { Jx4"~ 4
%tJ@)
!O*uQB
public Utility() xE%sPWbj
{ Vrx3%_NkQ
$WHmG!)*
B0eKj=y;
} qB44;!(
8:)itYE
//线程睡眠 eJtfQ@?
public static void sleep(int nSecond) (b>B6W\&
{ x#,nR]C
try{ "qvJ-Y
Thread.sleep(nSecond); W<s5rMx
} <c$K3
catch(Exception e) Q=Y1kcTOn
{ UfAN)SE"
e.printStackTrace (); Mg76v<mv<
} ?wYvBFRn7"
} eIY![..J/N
h!h<!xaclW
//日志 :~{x'`czJ
public static void log(String sMsg) :ZP`Y%dt'
{ ^TCgSi7k`L
System.err.println(sMsg); qJPEq%'Q
} w.6Gp;O
%q)*8
g6Nw].{
public static void log(int sMsg) a2\r^fY/
{ 52>,JHq
System.err.println(sMsg); DQRr(r~2Kj
} yi$Jk}w
} ohj(1jt
|B/A)(c yV
AEr8^6
/* !$5.\D
**TestMethod.java FF7
*/ Ua=w;h
package NetFox; !<I3^q
S@PAtB5
t;e+WZkV
public class TestMethod { T.kQ] h2ZG
6e.?L
BmGY#D,
public TestMethod() P]b *hC
{ ///xx/weblogic60b2_win.exe Y] "_}
try{ ZAcH`r*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^wm>\o;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &]mZp&
SiteFileFetch fileFetch = new SiteFileFetch(bean); re;^,
fileFetch.start(); HHU0Nku@ho
} Q1?09
catch(Exception e){e.printStackTrace ();} g8^YDrH
fF*{\
N! N>/9
} DsZBhjCB
eH9Ofhsry
/<WK2G
public static void main(String[] args) b ?-VZA:
{ N akSIGm
new TestMethod(); fXJbC+
} [TFd|ywn
} sq~9 l|F
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