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)); 6Eu&%`
} TAXl73j_CY
for(int i=0;i<nEndPos.length-1;i++) =z]8;<=pL
{ l}Fa-9_'
nEndPos = nStartPos[i+1]; Q<e`0cu|p
} WecJ^{g>r{
nEndPos[nEndPos.length-1] = nFileLength; TYs#v/)I
} SdI/
} 2k^dxk~$V;
wG&+*,}
ilyQgEjC
//启动子线程 o`@B*, @
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0 CJ4]mYl
for(int i=0;i<nStartPos.length;i++) .QhH!#Y2D
{ #=MQE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T21SuM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rCmxv7" a}
nStartPos,nEndPos,i); BBg&ZIYEh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >QusXD"L>
fileSplitterFetch.start(); ? }k~>. \
} 7 %P?3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x%;Q /7&$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cZ" Ut
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GC3:ZpV`
nEndPos = " + nFileLength); zn |=Q$81
// fileSplitterFetch[nPos.length-1].start(); j=^b'dyL
`P`nqn
GM/3*S$c
//等待子线程结束 '(/ZJ88JP
//int count = 0; S*H :/Ip
//是否结束while循环 !n`ogzOh
boolean breakWhile = false; 6g ,U+~
}G8RJxy
V.IgEE]
while(!bStop) !d1}IU-h
{ {C%/>e2-%
write_nPos(); lA4Bq
Utility.sleep(500); |wf:|%
breakWhile = true; /HNZwbh]uJ
t9&z|?Vz
?80@+y]
for(int i=0;i<nStartPos.length;i++) ]|q\^k)JU
{ ];P^q`n=.
if(!fileSplitterFetch.bDownOver) tUmI#.v
{ b'$j* N
breakWhile = false; JlsRP
break; A a2*f[
} %J`;
} 4/{Io &|
if(breakWhile) j$*]'s&_hZ
break; 'JEZ;9}
+q]
VI%879Z\e
//count++; DPnKr/
//if(count>4) p[e|N;W8A
// siteStop(); !MB%
} RB_7S!qC5
0k5Zl?
I~S`'()J
System.err.println("文件下载结束！"); Z*kGWL
} wLD/#Hfi7
catch(Exception e){e.printStackTrace ();} 1h\:Lj
} RR:m<9l
}H{{@RU
=&,zWNz)
//获得文件长度 yXNE2K
public long getFileSize() GI$t8{M
{ hQBeM7$F_
int nFileLength = -1; v,RLN`CID
try{ i^uC4S~
URL url = new URL(siteInfoBean.getSSiteURL()); +[r%y,k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wCBL1[~C
httpConnection.setRequestProperty("User-Agent","NetFox"); 8N(bLGUG
dv%gmUUf}k
Fm-W@
int responseCode=httpConnection.getResponseCode(); 'oTcx Jx
if(responseCode>=400) m7kDxs(KO
{ P58U8MEG
processErrorCode(responseCode); )?pin|_x
return -2; //-2 represent access is error 1l\O9D +$
} scqG$~O)
a-Cp"pKlVY
P1 (8foZA
String sHeader; K4n1#]8i
$t1]w]}d
GU'5`Yzd9
for(int i=1;;i++) 9;Wz;p
{ /^uvY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $2>tfKhtA
//Utility.log(in.readLine()); FTCp3g
sHeader=httpConnection.getHeaderFieldKey(i); jXi<ZJ
if(sHeader!=null) :c)<B@NqNo
{ 35RH|ci&
if(sHeader.equals("Content-Length")) tb/u@}")
{ 'xStA
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Jkm\{;
break; ]vQo^nOo
} +@%9pbM"z
} rxa"ji!)
else YhLtf(r
break; J-?\,N1R7
} ~8pf.^,fi
} !kASEjFz|f
catch(IOException e){e.printStackTrace ();} e,~c~Db* Q
catch(Exception e){e.printStackTrace ();} dN |w;|M
|J(]
308w0eP
Utility.log(nFileLength); A$XjzTR
Q=PaTh
`Q(ac| 0
return nFileLength; 7=QV^G
} }lpcbm
crgYr$@s?
~BS*x+M
//保存下载信息（文件指针位置） i $I|JJJ
private void write_nPos() M8cLh!!
{ x;Gyo
try{ t_]UseP$RF
output = new DataOutputStream(new FileOutputStream(tmpFile)); [PX'Jer
output.writeInt(nStartPos.length); 6{7O
for(int i=0;i<nStartPos.length;i++) pHg8(ru|
{ ^G2vA8%
// output.writeLong(nPos); M\v4{\2l0
output.writeLong(fileSplitterFetch.nStartPos); "BFW&<1
output.writeLong(fileSplitterFetch.nEndPos); qsk71L
} 5\4>H6
output.close(); Z,4=<;PF
} +:'Po.{"
catch(IOException e){e.printStackTrace ();} _ZS<zQ'
catch(Exception e){e.printStackTrace ();} B:mlBSH
} $s]@%6f
_r8AO>
SD.ze(P
//读取保存的下载信息（文件指针位置） #[[p/nAy}A
private void read_nPos() "V^jAPDXb
{ _b5iR<f
try{ -+PPz?0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bs`/k&'
int nCount = input.readInt(); \!^o<$s.G
nStartPos = new long[nCount]; ]yIy~V
nEndPos = new long[nCount]; xK y<o
for(int i=0;i<nStartPos.length;i++) &&y@/<t
{ X_YD[
nStartPos = input.readLong(); =f|>7m.p
nEndPos = input.readLong(); |1<Z3\+_/
} ~%}g"|o
input.close(); b,`\"'1
} eS.]@E-T
catch(IOException e){e.printStackTrace ();} (i?^g &
catch(Exception e){e.printStackTrace ();} _0f[.vN
} Z*QRdB%,
Y$Ke{6 4
/<2_K4(-{4
private void processErrorCode(int nErrorCode) d{trO;%#f
{ h/k`+
System.err.println("Error Code : " + nErrorCode); lz*2wGI9
} n$?oZ*;
Lf:Z (Z>
;8v5 qz
//停止文件下载 avz 4&
public void siteStop() >@%!r
{ W6iIL:sp
bStop = true; 8(I"C$D!k
for(int i=0;i<nStartPos.length;i++) lt4UNJ3w
fileSplitterFetch.splitterStop(); (BGipX4
MDq@:t
Sce9R?II
} 1_QO>T'
} t(yv
//负责部分文件的抓取 CMr`n8M
**FileSplitterFetch.java ')aYkO{%sb
*/ dWUu3
package NetFox; Ll`apKr
6{~I7!m"
5 9vGLN!L
import java.io.*; 4jW{IGW
import java.net.*; IviWS84
k?#6j1pn
IW#(ICeb
public class FileSplitterFetch extends Thread { <*+MBF
88K*d8m
0>`69&;g|
String sURL; //File URL 0{yx*}.
long nStartPos; //File Snippet Start Position 'nno)kQ"
long nEndPos; //File Snippet End Position 1}pR')YL[
int nThreadID; //Thread's ID -*A'6%`
boolean bDownOver = false; //Downing is over ]*|K8&jxl
boolean bStop = false; //Stop identical #o RUH8
FileAccessI fileAccessI = null; //File Access interface ZS+2.)A
vn<S"
(G VGoh&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UQ)}i7v
{ Kf4z*5Veqr
this.sURL = sURL; ?zEF?LJoK
this.nStartPos = nStart; f+V':qz
this.nEndPos = nEnd; E'G>'cW;x
nThreadID = id; qo;\dp1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?MH4<7?"
} TRZ^$<AG
l_c?q"X
|@BN+o;`Om
public void run() q1y4B`
{ 4_<Uk
while(nStartPos < nEndPos && !bStop) (=j!P*
{ K^Ht$04
Ie"R,,c
Z3dd9m#.]
try{ ^ne8~ ;Q
URL url = new URL(sURL); B]7jg9/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %j@FZ )a[
httpConnection.setRequestProperty("User-Agent","NetFox"); 7o. 'F
String sProperty = "bytes="+nStartPos+"-"; 8GldVn.u
httpConnection.setRequestProperty("RANGE",sProperty); \0h/~3
Utility.log(sProperty); TXcKuo=
VaxO L61xE
iC]lO
InputStream input = httpConnection.getInputStream(); lG9ARRy(=
//logResponseHead(httpConnection); L])w-
_GqE'VX
}=a4uCE
byte[] b = new byte[1024]; "N]o5d
int nRead; mx~sxYa
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .h,xBT`}Ji
{ sE6J:m(
nStartPos += fileAccessI.write(b,0,nRead); 9eiBj
//if(nThreadID == 1) c'";36y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2(Uz9!<V
} =joXP$n^
Bq@wS\W>b}
\F~Cbj+'Nu
Utility.log("Thread " + nThreadID + " is over!"); 2p>SB/
bDownOver = true; ^z^e*<{WEl
//nPos = fileAccessI.write (b,0,nRead); 5Q`n6x|
} 9^ p{/Io
catch(Exception e){e.printStackTrace ();} /T)n5X
} 4Z9wzQ>
} Z4ioXl
mndl~/
JWHt|zBg
//打印回应的头信息 R Sz[6
public void logResponseHead(HttpURLConnection con) JyC&L6[]Z
{ xc.D!Iav
for(int i=1;;i++) 8? Wxd65)
{ [P=[hj;
String header=con.getHeaderFieldKey(i); ^!o}>ls['
if(header!=null) {@__%=`CCS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2pa3}6P+
Utility.log(header+" : "+con.getHeaderField(header)); Uy5!H1u
else +\GZ(!~
break; ,,%:vK+V
} 2BX GVo
} +'KE T,
'QojSq
heZy 66
public void splitterStop() <3=qLm
{ kN|5 J
bStop = true; 5}bZs` C
} nVn|$ "r
=yX&p:-&
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} )9L pX
_T|H69 J
a,*p_:~i
/* Yz-JI=
**FileAccess.java uO@3vY',n
*//文件访问(定位，写) Ocwp]Mut&
package NetFox; U5CPkH1
import java.io.*; ^qGA!_
=lC;^&D-0/
}"?nU4q;S
public class FileAccessI implements Serializable{ )w2K&Zr0
\!JS7!+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 N^ s!!Sbpq
RandomAccessFile oSavedFile; Zfy~mv$
long nPos; -}X?2Q
H >:4MY
7ec0Xh1
public FileAccessI() throws IOException /ggkb8<3
{ Fu4EEi
this("",0); uR:=V9O
} yw.~trF&%
:Wg-@d
w;c#drY7S
public FileAccessI(String sName,long nPos) throws IOException o"#TZB+k
{ y=9Dxst"V
oSavedFile = new RandomAccessFile(sName,"rw"); _jTwiuMS-
this.nPos = nPos; f(6UL31
oSavedFile.seek(nPos); Xqg.kX
} Ln=>@
$89ea*k
xaWGa1V'z
public synchronized int write(byte[] b,int nStart,int nLen) VX;zZ`BJ
{ *5y W
int n = -1; 6h2x~@
try{ T)(e!Xz
oSavedFile.write(b,nStart,nLen); F)/~p&H
n = nLen; X a"XB
} 4|6&59?pnc
catch(IOException e) X'FEOF
{ ,@Fgr(?'`>
e.printStackTrace (); &[5n0e[
} $N;"}Gz
[,<\RviI
[`.3f'")j
return n; ,u}<Ws8N
} .pM &jni Y
s(AJkO'`
k,,!P""
} Fn86E dFM
Dac ^*k=D
j:3EpD@GS
/* vpm ]9>1[
**SiteInfoBean.java 0)d?Y
*/ T?X^0UdJj
package NetFox; +/y{^}b/
T8$%9&j!UE
rI0)F
public class SiteInfoBean { 3sZ,|,ueD
ybZ}
h/I@_?k+
private String sSiteURL; //Site's URL cMDRWh
private String sFilePath; //Saved File's Path s$DGd T)
private String sFileName; //Saved File's Name ~J0,)_b%*
private int nSplitter; //Count of Splited Downloading File \F 3C=M@:
Gn]d;5P=
dgS4w@)@V;
public SiteInfoBean() S8O)/Sg=
{//nSplitter的缺省值为5 7p)N_cJD
//default value of nSplitter is 5 |d $1wr
this("","","",5); *(k%MTG
} X[V?T>jsM
_yj1:TtCNT
}>V/H]B
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~xS@]3n=
{ 42fprt
sSiteURL= sURL; ^8:VWJM
sFilePath = sPath; }6).|^]\'
sFileName = sName; 8N%z9b
this.nSplitter = nSpiltter; nO~b=qO
%yiD~&
<EtUnj:qK8
} B&?fM~J
}2lO _i}L
25d\!3#E
public String getSSiteURL() `gt:gx>a
{ %`#G92Z_
return sSiteURL; a mqOxb
} 4otl_l(`yv
%y>+1hakkX
lW p~t
public void setSSiteURL(String value) T|ZF/&XP
{ a:A n=NA
sSiteURL = value; t05_Px!mW
} Uo2+:p
:r&iMb:Ra
jyiFM5&
public String getSFilePath() `mzb(bE
{ q +R*Hi
return sFilePath; 'w(y J
} -/>9c-F
OUzR@$
o~#f1$|Xn
public void setSFilePath(String value) }X]\VSF{
{ !EOQhh
sFilePath = value; QdDObqVdy
} `?|Rc
}B0sC%cm
%x2uP9
public String getSFileName() ~.Cv DJy
{ k#C f})
return sFileName; ~-_i
} i5"5&r7r
edijfhn
CvK3H\.&;k
public void setSFileName(String value) _({@B`N}
{ =A@>I0(7
sFileName = value; 6YmP[%
} l4vTU=
nO{ x^b <
@vRwzc\
public int getNSplitter() 8[zb{PRu
{ bO3GVc+S
return nSplitter; *}cSE|S%
} >{5 p0
T#EFXHPr
&gn-Wb?
public void setNSplitter(int nCount) 2q PhLCeZ
{ I[0!SIqY
nSplitter = nCount; >2b`\Q*<
} khx.yRx
} gCuAF$o
V.6)0fKZW
gEwd &J
/* sw;|'N$:<
**Utility.java 5\hd4
*/ .[:VSM7T
package NetFox; HYCuK48F[_
tfYB_N
h3!$r~T!a:
public class Utility { +G*JrwJ&=
'<dgT&8C
8'#/LA[uPe
public Utility() w1`QIv
{ ,LhCFw{8?~
< zOi4v0
65TfFcQ<S
} 7 oQ[FdRn*
DM{ 4@*]
//线程睡眠 ;H'gT+t<c
public static void sleep(int nSecond) ,q#0hy%5/
{ ZnW@YC#9
try{ !H@0MQ7
Thread.sleep(nSecond); #Sh <Ih
} J00VTb`
catch(Exception e) #8XL :I
{ 9'[ N1Un.=
e.printStackTrace (); +4))/`DA
} _; Y`
} U_B((Z(g
%NHkDa!
//日志 wkUlrL/~
public static void log(String sMsg) p-GAe,2q
{ ZcJ\ZbE|
System.err.println(sMsg); m ci/'b Xt
} 72W s K"
&;&ho+qD
)2IH 5
public static void log(int sMsg) d5`3wd]]'v
{ v'!a\b`9
System.err.println(sMsg); v\tEVhm
} iB[~U3
} **3 z;58i
s$D ^>0
;r[@v347
/* 9h4({EE2t
**TestMethod.java (xHf4[[u
*/ o1cErI&q"
package NetFox; G+UMBn
4%nE*H%
a`[uNgDO
public class TestMethod { Qv,"($n\
/1mW|O>0
}G4ztiuG
public TestMethod() t3(]YgF
{ ///xx/weblogic60b2_win.exe eIRLNxt+v
try{ E;JsBH
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -K9c@?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); gL_Y,A~Q{
SiteFileFetch fileFetch = new SiteFileFetch(bean); l&iq5}[n&
fileFetch.start(); 7(5xL T$
} pn.wud}R
catch(Exception e){e.printStackTrace ();} P9g en6
=6"2UC&
'Vyt4^$%
} ?7<JQh)"e
91=OF*w
At7>V-f}
public static void main(String[] args) vnWWneeNr
{ Tb3J9q+ya
new TestMethod(); d ,4]VE
} Ut2y;2)a
} ?c[*:N(
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