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)); I8~ .Vu2
} cetHpU,
for(int i=0;i<nEndPos.length-1;i++) UVa:~c$U4
{ H2[VZ&Pg
nEndPos = nStartPos[i+1]; utOATjB.z
} *9Ta0e*
nEndPos[nEndPos.length-1] = nFileLength; `s1>7XWf
} @pq2Z^SQH
} $1lI6 = ,
mWEaUi)Zz
l ld,&N8
//启动子线程 +5~5BZP
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; J,q6
for(int i=0;i<nStartPos.length;i++) Uao8#<CkvJ
{ 0i/!by{@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ),cozN=NM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Xf 0)i
nStartPos,nEndPos,i); u*}[fQ`aF
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tV.qdy/]}
fileSplitterFetch.start(); ]rC2jB\,M
} 76 nrDE
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \EI<1B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J34/rL/s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3QSA|
nEndPos = " + nFileLength); }OZut!_
// fileSplitterFetch[nPos.length-1].start(); l/*NscYtQ
l$_q#Kd
OeMI
//等待子线程结束 vX?MB
//int count = 0; Lsu_f'p0
//是否结束while循环 #dO8) t
boolean breakWhile = false; qe^d6
k|uW~I)
80m<OW1
while(!bStop) fhwJ
{ D@W[Nd5MJ
write_nPos(); k65V5lb
Utility.sleep(500); _"0,
breakWhile = true; 7+]+S`p
~t=73fwB
iEx sGn]2
for(int i=0;i<nStartPos.length;i++) ]F'o
{ vC#_PI
if(!fileSplitterFetch.bDownOver) |NMf'$
{ 3g79pw2w=
breakWhile = false; b6(LoN.
break; -ElK=q
} {4]sJT
} vD-m FC)
if(breakWhile) Kx4_`;>
break; YzA6*2
yV.E+~y
#!.26RM:P
//count++; wqnrN6$jf
//if(count>4) eeMeV>
// siteStop(); sh#hDU/</
} \:mZ)f3K=
TKH!,Ow9A
%>io$o
System.err.println("文件下载结束！"); npCiqO
} ,vcg%~-
catch(Exception e){e.printStackTrace ();} Q$bi:EyJXc
} 1`& Yg(
JX)%iJq#
wjzR 8g0bQ
//获得文件长度 Qr.SPNUFK
public long getFileSize() n=F|bW
{ OK]_.v}
int nFileLength = -1; 9B)<7JJX!J
try{ 0 k(su
URL url = new URL(siteInfoBean.getSSiteURL()); e'l@M$^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q 3nF\Me0
httpConnection.setRequestProperty("User-Agent","NetFox"); l/i7<q
?+P D?c7
0PP5qeqN2n
int responseCode=httpConnection.getResponseCode(); H@uDP
if(responseCode>=400) -prc+G,qyp
{ %|izt/B
processErrorCode(responseCode); DS|HN
return -2; //-2 represent access is error XG!s+ShFV
} :aHLr[%Mz
O3JBS^;V2
>OxSrc@A
String sHeader; q?##S'
;h~v,h
^]zC~LfG
for(int i=1;;i++) ']&rPvkL
{ Cs2F/M'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dbsD\\,2%N
//Utility.log(in.readLine()); Lk8[fFa4
sHeader=httpConnection.getHeaderFieldKey(i); h uIvXl
if(sHeader!=null) ."u DM<
{ 9aoGptgN
if(sHeader.equals("Content-Length")) h_y;NB(w
{ (3VV(18
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =O o4O CF2
break; w,x'FZD
} ISDeLUihY
} +1pY^#A
else /idrbc
break; *Dhy a g
} s(0"r.
} Hx?OCGj=S*
catch(IOException e){e.printStackTrace ();} yx\I&\i
catch(Exception e){e.printStackTrace ();} M5Q7izM
PRi1 `%d
b haYbiX?
Utility.log(nFileLength); f&2f8@
/H'F4->
[bh8Nj\E
return nFileLength; igO,Ge8}
} Qq{>]5<
%] #XIr
t3 rQ5m
//保存下载信息（文件指针位置） mmvo >F"
private void write_nPos() 9#MY(Hr
{ jU2vnGw_
try{ p0sq{d~
output = new DataOutputStream(new FileOutputStream(tmpFile)); o>jM4sk$
output.writeInt(nStartPos.length); c( 8>|^M
for(int i=0;i<nStartPos.length;i++) ?}ly`Js
{ "CY#_)
// output.writeLong(nPos); _Squ%z:D
output.writeLong(fileSplitterFetch.nStartPos); b-OniMq~
output.writeLong(fileSplitterFetch.nEndPos); GX#SCZ&}C
} =im7RgIBo
output.close(); J ?^R1
} xcM*D3
catch(IOException e){e.printStackTrace ();} 6d{&1-@>
catch(Exception e){e.printStackTrace ();} (iJ9ekB
} xe@11/F
Vo`,|3^
8Cef ]@x
//读取保存的下载信息（文件指针位置） E(-@F%Q
private void read_nPos() "n%0L4J
{ kNk$[Yfs
try{ ~]V}wZt>h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8nE}RD7bx
int nCount = input.readInt(); 0K'^g0G
nStartPos = new long[nCount]; $I|6v
nEndPos = new long[nCount]; r7Zx<c
for(int i=0;i<nStartPos.length;i++) =-%10lOI
{ PD$' ~2
nStartPos = input.readLong(); LQz6op}R
nEndPos = input.readLong(); ^-2|T__
} yp?a7t M
input.close(); %DhM}f
} uA;vW\fHr
catch(IOException e){e.printStackTrace ();} C8W4~~1S
catch(Exception e){e.printStackTrace ();} 9D[Jn}E:
} 73kU\ux
0WI@BSHnM
11YpC;[o
private void processErrorCode(int nErrorCode) eufGU)M
{ b <z)4
System.err.println("Error Code : " + nErrorCode); h/pm$9A
} C @nA*
/C
D^)?*(
//停止文件下载 !]C=5~BBI
public void siteStop() 8)bqN$*h
{ gT{WH67u
bStop = true; W)jtTC7
for(int i=0;i<nStartPos.length;i++) k9m9IE"9=$
fileSplitterFetch.splitterStop(); \'CA:9V}
"I,=L;p
Xrr3KQaK&
} H&SoVi_V
} o2rL&
//负责部分文件的抓取 D~b_nFD
**FileSplitterFetch.java ;Q>+#5H6F8
*/ Ox%p"xuP,
package NetFox; (sqI:a
e#odr{2#4u
:^rt8>~
import java.io.*; 0b(x@>
import java.net.*; X" Upml
mlix^P
c^1tXu|&
public class FileSplitterFetch extends Thread { $*+IsP!
sc&u NfJ
sR;u#".
String sURL; //File URL Xv<K>i>k
long nStartPos; //File Snippet Start Position "cz'|z`
long nEndPos; //File Snippet End Position n?:%>Os$
int nThreadID; //Thread's ID ?egZkg=U
boolean bDownOver = false; //Downing is over Q N]y.(S)y
boolean bStop = false; //Stop identical A/!"+Yfw
FileAccessI fileAccessI = null; //File Access interface '!<gPAVTzV
jSMxba]
mqK}yK^P]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @!Rklhb
{ Q.,2G7[ <
this.sURL = sURL; #Q1}h
this.nStartPos = nStart; T#.pi@PF>
this.nEndPos = nEnd; 7 T
nThreadID = id; 5m2f\^U
fileAccessI = new FileAccessI(sName,nStartPos);//定位 j;BlpRD}
} \l1==,wk
k}0b7er=R
"1Y'VpKm(~
public void run() yT-qT_.
{ a4&Aw7"X
while(nStartPos < nEndPos && !bStop) [H@71+_Q
{ dJ{q}U
iAo/Dnp2J
d_7hh
try{ IictX"3lh
URL url = new URL(sURL); \}71pzw(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3X%h?DC
httpConnection.setRequestProperty("User-Agent","NetFox"); E NrcIZ
String sProperty = "bytes="+nStartPos+"-"; <q&4Y+b
httpConnection.setRequestProperty("RANGE",sProperty); 8d7 NESYl
Utility.log(sProperty); Y_<-.?jf
..7"<"uH
s_}`TejK
InputStream input = httpConnection.getInputStream(); cH6++r
//logResponseHead(httpConnection); :-Ml?:0_X
[@_W-rA
.(99f#2M:
byte[] b = new byte[1024]; Wv||9[Rd
int nRead; &2bqL!k
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "7Z-ACyF5
{ [\qclW;L
nStartPos += fileAccessI.write(b,0,nRead); mKsJ[)#.
//if(nThreadID == 1) ~REfr}0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [2PPa9F
} ;0lY_ii
_2TL>1KZt
24u_}ZQzY
Utility.log("Thread " + nThreadID + " is over!"); _#qfe
bDownOver = true; qrf90F)
//nPos = fileAccessI.write (b,0,nRead); szCB}WY
} dNf:I,<DCf
catch(Exception e){e.printStackTrace ();} )|/%]@` N
} g`C\pdX"B
} <eZ*LK?
[HI$[:[
U!(es0rX
//打印回应的头信息 _2Mpzv
public void logResponseHead(HttpURLConnection con) qw 03]a
{ ~F8xXW0
for(int i=1;;i++) wXtp(YwlH
{ Y,Lx6kU
String header=con.getHeaderFieldKey(i); 5>lIrBf
if(header!=null) &->ngzg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); '&nQ~=3
Utility.log(header+" : "+con.getHeaderField(header)); M@o^V(j
else S=j pn
break; JvK]EwR ;
} >}:
} 1m5*MY
n,d)Wwe_`y
s(KSN/
public void splitterStop() bz}-[W+
{ .TCDv4?
bStop = true; pD('6C;
} !hFhw1
4xH/a1&p=
jweX"G54R
} rsq?4+\
ac\([F-
hI9q);g
/* kD0bdE|
**FileAccess.java +I?k8',pi
*//文件访问(定位，写) 4,>9N9.?9
package NetFox; P)cEYk
import java.io.*; !6x7^E;c
CW2)1%1iz
G:3szz
public class FileAccessI implements Serializable{ C T\@>!'f
7WwE] ^M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b;%t*?t
RandomAccessFile oSavedFile; lh[?`+A
long nPos; Z #T
Y2;2Exp^
T];dFv-GT
public FileAccessI() throws IOException ]x{.qTtw
{ r?IBmatK/
this("",0); 0zE@?.
} UOk\fyD2[
rOz1tY)l0d
4v`IAR?&K;
public FileAccessI(String sName,long nPos) throws IOException .!Pg)|
{ #?V rt,n
oSavedFile = new RandomAccessFile(sName,"rw"); Inn{mmz 1
this.nPos = nPos; %pxO<O
oSavedFile.seek(nPos); *\(z"B
} * k<@
aZ+><1TD
zgH(/@P
public synchronized int write(byte[] b,int nStart,int nLen) U`lK'..
{ tU5uL.( O
int n = -1; dt^h9I2O
try{ mBE&>}G<
oSavedFile.write(b,nStart,nLen); P#,;)HF
n = nLen; *yaS^k\
} :W5W @8Y
catch(IOException e) _CfJKp)
{ yIrJaS-
e.printStackTrace (); eZaSV>27
} I/%v`[
?C#E_
y)U?.@
return n; #c5jCy}n
} fx(h fz
Pc_aEBq
D}q"^"#T
} }f]Y^>-Ux
_'LZf=V0
-(t7>s
/* pF4Z4?W
**SiteInfoBean.java =E5bM_P<K
*/ __2<v?\
package NetFox; P RWb6
Qr9;CVW
?oFd%|I
public class SiteInfoBean { 6,aH[>W
,/D}a3JD
bh<;px-
private String sSiteURL; //Site's URL Dlq!:dF{&
private String sFilePath; //Saved File's Path KWZhCS?[(
private String sFileName; //Saved File's Name Zym6btc
private int nSplitter; //Count of Splited Downloading File qh:Bc$S
Aeb(b+=
-cM1]soT
public SiteInfoBean() ^J5{quV
{//nSplitter的缺省值为5 IQRuqp KL
//default value of nSplitter is 5 v6s,lC5qR
this("","","",5); B*,)@h
} 0Gc@AG{
d<6F'F^w.7
1^4:l!0D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )](ls@*
{ @Fb1D"!
sSiteURL= sURL; +yp:douERi
sFilePath = sPath; Z*ip=FYR
sFileName = sName; d=PX}o^
this.nSplitter = nSpiltter; N+=|WeZ
,|{`(y/v
/{\ /e"5
} ,^1zG
mK[Z#obc=
;^5k_\
public String getSSiteURL() n7cy[%yT
{ ch8a
return sSiteURL; n4/Wd?#`
} `8ac;b
s*ZE`/SM3
kFv*>>X`
public void setSSiteURL(String value) t$18h2yOL
{ d )O^(y1r
sSiteURL = value; e@Lxduq
} =~GP;=6
(Jk&U8y
q(6.VU@
public String getSFilePath() n^Ca?|} ,
{ Y%.o TB&
return sFilePath; nt#9j',6Rn
} OT%E|) 6'
94rSB}b.O
j#1G?MF
public void setSFilePath(String value) lh8QtPe
{ P.'.KZJ:WD
sFilePath = value; @up,5`
} %.Ma_4o Z
C9!t&<\}
iT>u&0B-
public String getSFileName() mGjB{Q+
{ *M1GVhW(+
return sFileName; :V(LBH0
} 0O9b 7F
C#kE{Qw10r
^#HaH
public void setSFileName(String value) 7k(}U_v
{ !6KX^j-
sFileName = value; Y%XF64)6
} *siX:?l
~U0%}Bbh
|O{N_-];.
public int getNSplitter() &-3e3)
{ 2R[v*i^S
return nSplitter; >}+{;d
} fg^AEn1i
#ibwD:{
fp)SZu_*
public void setNSplitter(int nCount) g2vm]j
{ U?*zb
nSplitter = nCount; yQ$irS?
} wa"0`a:`;
} U.e!:f4{
[';o -c"!
5/=$p:E>
/* o,*m,Qc
**Utility.java /)ZjI W"|
*/ uNN/o}Qx
package NetFox; OS(`H5D
EYT^*1,E*
_:r8UVAT.
public class Utility { (a[BvJf
@t%da^-HS"
.U!EA0B
public Utility() \ND]x]5d
{ M|(VM=~
X+4Uh I
9@*pC@I)
} h4hAzFQ.s
?"yjgt7+y
//线程睡眠 !j6k]BgZ
public static void sleep(int nSecond) s41%A2Enh
{ <Wn~s=
try{ + -<8^y
Thread.sleep(nSecond); [vi =^
} '12m4quO
catch(Exception e) S7+>Mk
{ y\FQt];z)
e.printStackTrace (); u$\.aWol
} #{6VdWZ
} xWxHi6U(
*~PB
//日志 LIDi0jbrq
public static void log(String sMsg) S5).\1m h[
{ YWIA(p8Qkk
System.err.println(sMsg); G*=HjLmZg
} !VD$uT
(HAdr5
ygz2bHpD~
public static void log(int sMsg) Zux L2W
{ w7MRuAJ4
System.err.println(sMsg); x1@,k=qrd
} >WZ.Dj0n
} F'uqL+jVO
:` SIuu~@
4@{;z4*`
/* D$FTnY
**TestMethod.java H:G``Vq;0m
*/ D <iG*I
package NetFox; (%^C}`|EA
nAP*w6m0j
MHpGG00,
public class TestMethod { [vu;B4^"
{QEvc
+Z"Wa0wA
public TestMethod() =c6d$
{ ///xx/weblogic60b2_win.exe ^tTM 7
try{ rCo}^M4Pb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9O- otAGM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); c44s@E
SiteFileFetch fileFetch = new SiteFileFetch(bean); /[/L%;a'p
fileFetch.start(); #'/rFT4{v
} =ls+vH40&
catch(Exception e){e.printStackTrace ();} JrBPx/?(,;
Yup#aeXY/
tar/no
} R&!;(k0
;1~n|IY
nKE^km
public static void main(String[] args) "/R?XCBZsb
{ %qV:h#
new TestMethod(); T$kuv`?
} FO>?>tK 0
} UR^r>
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