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)); aQTISX;
} e6(Pw20)s
for(int i=0;i<nEndPos.length-1;i++) K!cLEG!G
{ b<]Ae!I'
nEndPos = nStartPos[i+1]; zQ=c6xvm8
} gd,3}@@SH
nEndPos[nEndPos.length-1] = nFileLength; T!F0_<
} YPU*T&~
} N+3]C9 2o
Y48MCL
#86=[*Dr
//启动子线程 >Hd0l L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >%?kp[
for(int i=0;i<nStartPos.length;i++) .:U`4->E
{ -V_iv/fmM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s-[v[w'E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <=g{E-
nStartPos,nEndPos,i); |3:e$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NU <K+k
fileSplitterFetch.start(); |}07tUq
} {}A1[Y|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'Y;M%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @,i_Gw)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U%?
nEndPos = " + nFileLength); A{IJ](5.kd
// fileSplitterFetch[nPos.length-1].start(); `Jv~.EF%
>[A7oH
)b7;w#%q
//等待子线程结束 ^K]`ZQjKC
//int count = 0; ,'%wadOo
//是否结束while循环 yOdh?:Imv
boolean breakWhile = false; Zai:?%^
O`rKxP
Fo:60)Lr
while(!bStop) }9FAM@x1K&
{ dR|*VT\
write_nPos(); >DSD1i+N
Utility.sleep(500); )a=58r07
breakWhile = true; L8WYxJ k
Kwmtt
J4l\
for(int i=0;i<nStartPos.length;i++) ;+3XDz v
{ nPRv.h
if(!fileSplitterFetch.bDownOver) N7l`-y
{ j-%@A`j;
breakWhile = false; ,"xr^@W
break; I8%Uyap{
} \nbGdka
} Tfow_t}\
if(breakWhile) =Y]'wb
break; Iss)7I
e{6I-5`|,#
9,J^tN@^
//count++; Zjq(]y
//if(count>4) qdQQt5Y'm
// siteStop(); ur@"wcl"V
} 8ZN"-]*
Gzw9E.Hk
2qgm(jo *y
System.err.println("文件下载结束！"); 30fqD1_{
} 7 /7,55
catch(Exception e){e.printStackTrace ();} Pu0 <Clh
} 3[r9v!l
O]cuJp
y3Qb2l
//获得文件长度 < pWk
public long getFileSize() &$NYZ3?9
{ <_>xkQbn2
int nFileLength = -1; kb~;s-$O`s
try{ CBKLct>
URL url = new URL(siteInfoBean.getSSiteURL()); {7Qj+e^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B }t529Z
httpConnection.setRequestProperty("User-Agent","NetFox"); yR$ld.[uf
es!>u{8)
kesuM3
int responseCode=httpConnection.getResponseCode(); 6qK`X
if(responseCode>=400) ,k |QuOrCh
{ M;j)F
processErrorCode(responseCode); m'PU0x
return -2; //-2 represent access is error y"T(Unvc
} {g7~e{2
(TTS-(
T?k!%5,Kj
String sHeader; qq'%9
|7)oX
)F'r-I%Hi
for(int i=1;;i++) :um]a70
{ Csf!I@}Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wO&+Bb\=
//Utility.log(in.readLine()); 36MNaQt'e
sHeader=httpConnection.getHeaderFieldKey(i); %?m_;iv
if(sHeader!=null) :y1,OR/k
{ #5yz~&
if(sHeader.equals("Content-Length")) HAmAmEc,
{ FjV)QP H
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V/Q/Ujgg
break; ((AIrE>Rr
} BF/l#)$yK
} =:*2t
else +5"Pm]oRbx
break; N1yx|g:
} $!7$0WbC
} C$4!|Wg3
catch(IOException e){e.printStackTrace ();} @MKf$O4K
catch(Exception e){e.printStackTrace ();} a)QSq<2*
8 -YC#&
!rTkH4!_
Utility.log(nFileLength); })umg8s
Vb,'VN%
x(7Q5Uk\
return nFileLength; td5! S]
} Q" G;L
Cg3 d
8k )i-&R
//保存下载信息（文件指针位置） m[qW)N:w
private void write_nPos() ;T :]?5W!
{ 4u=v
try{ Zg$RiQ^-{J
output = new DataOutputStream(new FileOutputStream(tmpFile)); zALtG<_t
output.writeInt(nStartPos.length); ."Q}2
for(int i=0;i<nStartPos.length;i++) TjS&V
{ 3(`P x}
// output.writeLong(nPos); ]cM,m2^2
output.writeLong(fileSplitterFetch.nStartPos); s)G?5Gz
output.writeLong(fileSplitterFetch.nEndPos); 7O,!67+^~
} d}<-G.&_
output.close(); -5Oy k,
} @?*; -]#)
catch(IOException e){e.printStackTrace ();} e2kW,JV/<$
catch(Exception e){e.printStackTrace ();} H'}6Mw%ra
} ,olP}
Y+{jG(rg.F
*uoO#4g~
//读取保存的下载信息（文件指针位置） oSLm?Lu
private void read_nPos() $"ACg!=M
{ QzxEkTc;
try{ JnLF61
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); sh*/wM
int nCount = input.readInt(); $f=6>Kn|^]
nStartPos = new long[nCount]; !oYNJE Y7
nEndPos = new long[nCount]; L*cP8v4
for(int i=0;i<nStartPos.length;i++) \_x~lRqJJ
{ NueuCiP
nStartPos = input.readLong(); h@dy}Id
nEndPos = input.readLong(); o4jh n[Fx
} pKU(4&BxX
input.close(); fr`Q 5!0
} gv){&=9/
catch(IOException e){e.printStackTrace ();} _'l"Dk
catch(Exception e){e.printStackTrace ();} Ol;DJV
} (4|R}jv
5\}E4y
qRHT~ta-?
private void processErrorCode(int nErrorCode) 2I283%xr
{ mpQu:i|W
System.err.println("Error Code : " + nErrorCode); =1y~Qlu
} dDa&:L
0U8'dYf
2"c5<
//停止文件下载 nl~Z,Y$
public void siteStop() R'8S)'l
{ 7CH.BY
bStop = true; 3taGb>15
for(int i=0;i<nStartPos.length;i++) Bru];%Qg%
fileSplitterFetch.splitterStop(); ^^F 8M0k3
0rvBjlFT
Eihy|p
} \VWgF)_
} 7Ah
//负责部分文件的抓取 LTB rg[X
**FileSplitterFetch.java Bg}l$?S
*/ BkP4.XRI
package NetFox; ;*0nPhBw0>
DTa!vg
iNc!zA4
import java.io.*; [SD mdr1T$
import java.net.*; P@D\5}*6
w OOu/Y
&TL"Hd
public class FileSplitterFetch extends Thread { u%lUi2P2E
?#Y:2LqPC
p{:y?0pGN
String sURL; //File URL {+GR/l\!#
long nStartPos; //File Snippet Start Position O<#8R\v
long nEndPos; //File Snippet End Position [$td:N *
int nThreadID; //Thread's ID d]:G#<.
boolean bDownOver = false; //Downing is over sVGQSJJ5
boolean bStop = false; //Stop identical ={f8s,m)P,
FileAccessI fileAccessI = null; //File Access interface 78r0K 5=
bYZU}Kl;(
><S(n#EB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X8ZO } X
{ h-RhmQA=Iz
this.sURL = sURL; {> 8?6m-
this.nStartPos = nStart; O;i0xWUh
this.nEndPos = nEnd; ,p /{!BX
nThreadID = id; ,7k-LAA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9_?e, Q
} BoST?"&}'
bwcr/J(Nb
8Lgm50bs
public void run() cD=IFOB*GD
{ ,I ][
while(nStartPos < nEndPos && !bStop) rV4K@)~
{ 8e^uKYR<
7!h> < sx
?L0k|7
try{ FvYciU!
URL url = new URL(sURL); (xoYYO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uubIL+
httpConnection.setRequestProperty("User-Agent","NetFox"); 17,mqXX>
String sProperty = "bytes="+nStartPos+"-"; +GL$[ 5G
httpConnection.setRequestProperty("RANGE",sProperty); SWY
Utility.log(sProperty); RgL>0s
V"'PA-z3
pPag@L
InputStream input = httpConnection.getInputStream(); 1r_V$o$
//logResponseHead(httpConnection); cIG7Q"4
"a}fwg9Y
z6rT<~xZtu
byte[] b = new byte[1024]; PHEQG]HS
int nRead; u"m(a:jQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^Il*`&+?P
{ `CC=?E
nStartPos += fileAccessI.write(b,0,nRead); A<"<DDy
//if(nThreadID == 1) 7S&$M-k
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EU>`$M&w-
} "P54|XIJ\
"tl$JbRTY
b GI){0A
Utility.log("Thread " + nThreadID + " is over!"); %+Y wzL{
bDownOver = true; >C!^%e;m
//nPos = fileAccessI.write (b,0,nRead); tl\<:8pI"
} |FM*1Q[1
catch(Exception e){e.printStackTrace ();} OXbShA&1
} h.F=Fhx/1
} 9=3DYCk/
j7Ts&;`[*
% @+j@i`&
//打印回应的头信息 \!BVf@>p%
public void logResponseHead(HttpURLConnection con) **kix
{ X(X[v]
for(int i=1;;i++) H,5]w\R6\
{ 3Jlap=]68S
String header=con.getHeaderFieldKey(i); 3X11Gl
if(header!=null) 7`&ISRU4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :?BK A0E
Utility.log(header+" : "+con.getHeaderField(header)); z\A ),;
else QDV+(
break; 9A} *
} rzn,NFI
} FX|&o>S(8
O>1Cx4s5
w:QO@
public void splitterStop() zU+q03l8Ur
{ u;-fG9xs
bStop = true; )Hmf=eoc
} ?_^{9q%9
_UPfqC ?
kDWEgnXK,v
} cPNc$^Y
J;8d-R5
X_hDU~5{wC
/* /B~[,ES@1
**FileAccess.java z<vh8dNl
*//文件访问(定位，写) h )5S4)
package NetFox; v/c]=/
import java.io.*; 9yC22C:
ZDbe]9#Xh
{DQ%fneN4
public class FileAccessI implements Serializable{ %}VH5s9\
UWvVYdy7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +|,4g_(j
RandomAccessFile oSavedFile; XgHJ Oqt
long nPos; -"dt3$ju
e@ZM&iR
rFQWgWD
public FileAccessI() throws IOException n@p@@
{ ={zTQ+7S`
this("",0); 3EICdC
} ^.!jD+=I
hyf ;f7`o
71{jedT
public FileAccessI(String sName,long nPos) throws IOException A+0-pF2D
{ r.\L@Y<
oSavedFile = new RandomAccessFile(sName,"rw"); nwUz}em?O
this.nPos = nPos; q_h (D/g
oSavedFile.seek(nPos); V&s|IoTR
} za@/4z
uwSSrT
0>N6.itOz
public synchronized int write(byte[] b,int nStart,int nLen) J4"Fj, FS
{ fyb;*hgu
int n = -1; Pp tuXq%U
try{ Jq'8"
oSavedFile.write(b,nStart,nLen); "U-jZ5o"
n = nLen; 5z!$=SFz
} XH$r(@Z\7
catch(IOException e) YiDOV)
{ '6 F-%
e.printStackTrace (); =x\`yxsG
} 7*{f*({
|2u=3#Jp
?!U[~Gq
return n; @I`^\oJ
} hDW!pnj1
|j`73@6
c Rq2 re
} VIP7j(#t_g
T+F]hv'
+ '_t)k^
/* LnI
**SiteInfoBean.java rQVX^
*/ {}$7Bp
package NetFox; EyE#x_A
w31Ox1>s
akzGJ3g
public class SiteInfoBean { F+V!p4G
L>h8>JvQ
nTEN&8Y>R
private String sSiteURL; //Site's URL Gs,:$Im
private String sFilePath; //Saved File's Path -V|"T+U
private String sFileName; //Saved File's Name %'=*utOxy
private int nSplitter; //Count of Splited Downloading File zXn-E
67II9\/
+O.-o/
public SiteInfoBean() 2M-[x"\1/
{//nSplitter的缺省值为5 P9 <U+\z
//default value of nSplitter is 5 &3[oM)-V
this("","","",5); I4X9RYB6c
} "%gsGtS
eyCZ[SC
h^yqrDyJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `GCoi ?n7
{ "tzu.V-
sSiteURL= sURL; 9Rnypzds
sFilePath = sPath; }aVZ\PDg
sFileName = sName; E+]9!fDy<
this.nSplitter = nSpiltter; N>!:bF
H4w\e#|
k2U*dn"9U
} ?BnU0R_r]
(j&:
\!-BR0+y;
public String getSSiteURL() "+F'WCJ-(*
{ EO&Q
return sSiteURL; "]+g5G
} JL1ajlm~
WEimJrAn
^Co$X+
public void setSSiteURL(String value) vwU1}H
{ >.iF,[.[F<
sSiteURL = value; a[-!X7,IU
} 69g{oo
`t~jHe4!Y
2s\ClT
public String getSFilePath() f2i:I1 p("
{ 08`|C)Z!
return sFilePath; #Vq9 =Q2
} :aesG7=O
E#B-JLMGl
?l0eU@rwQ
public void setSFilePath(String value) E7:xPNU
{ =:-fK-d
sFilePath = value; )(G9[DG
} HC%Hbc~S_Q
.A2$C|a*
=&WIa#!=
public String getSFileName() 'a['lF
{ 5?kfE
return sFileName; ?h= n5}Y
} v`HER6
nI\6aG?`
Y}:~6`-jj
public void setSFileName(String value) k{}> *pCU
{ 8h=t%zMSb
sFileName = value; f!9i6
} b2m={q(s
8QrpNSj4
j[G`p^ul
public int getNSplitter() }aZuCe_
{ >HP `B2Q H
return nSplitter; b(iF0U>&
} )kpEcMlR
N~v6K}`}
wVBKVb9N
public void setNSplitter(int nCount) i(}PrA
{ pHV^Kv#
nSplitter = nCount; r;#"j%z
} !6!)H8rX
} 6Y9N=\`
Kxr@!m"
x'GB#svi
/* !+GYu;_
**Utility.java T8XrmR&?PX
*/ C= ~c`V5>r
package NetFox; =&}@GsXdo
^4dE8Ve"@
s^h@b!'7
public class Utility { xE/?ncTK^
3gA%Q`"
2c `m=
public Utility() wPlM= .Hq?
{ jm}CrqU
9`tK9
Pe`(9&iT.
} C8U3+ s
T+kV~ w{
//线程睡眠 fkA+:j~z_
public static void sleep(int nSecond) mq`/nAmt
{ 6_CP?X+T
try{ !GcBNQ1p+7
Thread.sleep(nSecond); _olQ;{ U:
} 5'AP:3Gf"
catch(Exception e) nBh+UT}
{ 4Uy%wB
e.printStackTrace (); =)a24PDG
} cS ~OxAS
} 3:)z+#Uk6
ARKM[]
//日志 NXW*{b
public static void log(String sMsg) u,^CFws_
{ l2D*b93
System.err.println(sMsg); F2"fOS
} DB'v7 Ij0
st-{xC#N#
8Q'Emw |
public static void log(int sMsg) $%bSRvA
{ l/.{F;3F
System.err.println(sMsg); 5\mRH
} uYh!04u
} ]G/m,Zv*:
=RoG?gd{R
eV9U+]C`
/* Pvxb6\G&d
**TestMethod.java 3:J>-MO
*/ AGlBvRX7e
package NetFox; G@]3EP
^HKXm#vAB
oaIk1U;g
public class TestMethod { ~k"+5bHa*
@\K[WqF$$q
vsY?q8+P
public TestMethod() WtT;y|W
{ ///xx/weblogic60b2_win.exe 8=8hbdy;
try{ lx)^wAO4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @DN/]P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Fr9/TI
SiteFileFetch fileFetch = new SiteFileFetch(bean); w,UE0i9I
fileFetch.start(); JJ: ku&Mb
} >)>f~>
catch(Exception e){e.printStackTrace ();} gq=t7b
*1|7%*!8
ACszx\[K3
} ,06Sm]4L,
'Y38VOI%
]C_+u_9
public static void main(String[] args) 'VDWJTia
{ E~!$&9\
new TestMethod(); 7=^{~5#
} U3(+8}Q
} =[B\50]
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