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)); E[@ u 3i8
} G MX?
for(int i=0;i<nEndPos.length-1;i++) @|63K)Xy
{ \Zqng
nEndPos = nStartPos[i+1]; t<z`N-5*
} gv)P]{%^
nEndPos[nEndPos.length-1] = nFileLength; GT}F9F~
} TarIPp
} :(!`/#6H
%|g>%D3Z?
]B%v+uaW
//启动子线程 Jq&uF*!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H%UL%l$
for(int i=0;i<nStartPos.length;i++) im9G,e
{ Q<^Tl(`/N?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oX S1QT`B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E*V`":efS
nStartPos,nEndPos,i); OWjk=u2Lz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @eD):Y
fileSplitterFetch.start(); 9`I _Et
} hbzC#@q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;V*R*R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); aY'C%^h]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3DiLk=\~
nEndPos = " + nFileLength); 8\^}~s$$A
// fileSplitterFetch[nPos.length-1].start(); uxtWybv
,2j&ko1
TcjEcMw,
//等待子线程结束 \r /ya<5
//int count = 0; z3&]%Q&
//是否结束while循环 Ox&P}P0f
boolean breakWhile = false; (l-tvk4Ln
\6E|pbJ}x
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while(!bStop) F(k.,0Nc
{ !%^^\,
write_nPos(); Rn`x7(WA
Utility.sleep(500); Sp@^XmX(S
breakWhile = true; W-x?:X<}
M m[4yP%
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for(int i=0;i<nStartPos.length;i++) R:e<W/P"
{ e,F1Xi#d
if(!fileSplitterFetch.bDownOver) K/tRe/t}
{ @.b+av4J
breakWhile = false; lD^]\;?
break; )PG6gZYW
} pP*zq"o
} 9o;^[Ql-
if(breakWhile) A?CcHw rT
break; KM}f:_J*lg
@hJ%@(
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//count++; tw^,G(
//if(count>4) :*ing
// siteStop(); jNLw=
} {;N,t]>8M
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System.err.println("文件下载结束！"); :"=ez<t
} v@Gl|29_
catch(Exception e){e.printStackTrace ();} jX3,c%aQ5e
} bu:S:`
19O,a#{KHf
;pqg/>W'
//获得文件长度 w8kOVN2b
public long getFileSize() o*DN4oa)
{ (yF:6$:#
int nFileLength = -1; 4US"hexE<
try{ * mOo@+89
URL url = new URL(siteInfoBean.getSSiteURL()); 5jd,{<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |?qquD 4=
httpConnection.setRequestProperty("User-Agent","NetFox"); E"+QJ~!
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T(f/ ?_%
int responseCode=httpConnection.getResponseCode(); V}dJ.I /#
if(responseCode>=400) @!`Xl*l
{ 2] zq#6ix
processErrorCode(responseCode); /LO-HnJ
return -2; //-2 represent access is error f!s=(H;
} ptDY3n~'
;.TRWn#
X:6c}p%,!
String sHeader; 2Ou[u#H
+)y^'Qs
!P)O(i=
for(int i=1;;i++) Z?%zgqTXb
{ .Nw=[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;?8_G%va
//Utility.log(in.readLine()); ?,& tNP{jq
sHeader=httpConnection.getHeaderFieldKey(i); N'g>MBdI
if(sHeader!=null) cIav&Zko
{ 5qr'.m
if(sHeader.equals("Content-Length")) rcMwFE?|xq
{ TMig-y*[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~nrK>%
break; MFb9H{LA
} 4WJ.^(
} p4'G$]#
else v#.r.{t
break; {vuZ{IJa
} VxVE
} Ed_N[I
catch(IOException e){e.printStackTrace ();} =>M^02"
catch(Exception e){e.printStackTrace ();} #wV8X`g
fZ*+2T>
k&,~qoU
Utility.log(nFileLength); 8=gjY\Dp
I~ok4L?VB
`[W[H(AjQ
return nFileLength; LN@F+CyDc
} bI:zp!-.
i[?Vin
BFo5\l:q8
//保存下载信息（文件指针位置） tE)suU5Y
private void write_nPos() go'-5in(
{ %O!v"Xh
try{ T3k#VNH
output = new DataOutputStream(new FileOutputStream(tmpFile)); SV2M+5#;
output.writeInt(nStartPos.length); PX<J&rx
for(int i=0;i<nStartPos.length;i++) Q$="_y2cTA
{ c.>oe*+
// output.writeLong(nPos); 5u*-L_
output.writeLong(fileSplitterFetch.nStartPos); H;YP8MoQ
output.writeLong(fileSplitterFetch.nEndPos); >_|O1H./4
} /f|X(docI
output.close(); x "^Xj]-
} a{ ?`t|
catch(IOException e){e.printStackTrace ();} wid;8%m
catch(Exception e){e.printStackTrace ();} &NH$nY.r
} ">y%iE
^yyC [Mz
K':K{ee>
//读取保存的下载信息（文件指针位置） f;1K5Y
private void read_nPos() *#tJM.Z
{ 9983aFam
try{ :=wTvz
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7z!tKs"TMT
int nCount = input.readInt(); qoj$]
nStartPos = new long[nCount]; 2JJ"O|Ibz
nEndPos = new long[nCount]; CS==A57I
for(int i=0;i<nStartPos.length;i++) Z;:u'=
{ 763v
nStartPos = input.readLong(); *:L?#Bw
nEndPos = input.readLong(); +eFFSt
} 5A sP5
input.close(); pXJpK@z
} \H=&`?
catch(IOException e){e.printStackTrace ();} G-?d3n
catch(Exception e){e.printStackTrace ();} z#]Jv!~EPE
} #ZYVc|sT+
jF=gr$
rz@=pR :
private void processErrorCode(int nErrorCode) ds?v'|
{ 1rkE yh??
System.err.println("Error Code : " + nErrorCode); WIv?}gi: X
} 0IfKJ*]M
a^=-Mp
? P( ZA
//停止文件下载 uoXAQ6k
public void siteStop() >|twyb
{ {|1Y:&M?
bStop = true; jz5qQt]^
for(int i=0;i<nStartPos.length;i++) (Nx;0"5IX
fileSplitterFetch.splitterStop(); xv&Q+HD
brdmz}
l PK +$f$
} <K8\n^i~c
} 1;mW,l'`
//负责部分文件的抓取 U5He?
**FileSplitterFetch.java D,g1<:<
*/ 4Rvf
package NetFox; 8'f4 Od ?
/6h(6 *JI
w\DVzeW(
import java.io.*; -*m+(7G\
import java.net.*; Sp^9&^
vh*U]3@
-$WYj"
public class FileSplitterFetch extends Thread { UGuxV+Nwf
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String sURL; //File URL 1$81E.
long nStartPos; //File Snippet Start Position $.GOZqMs
long nEndPos; //File Snippet End Position XLH+C ]pfr
int nThreadID; //Thread's ID *H.oP
boolean bDownOver = false; //Downing is over *0>mB
boolean bStop = false; //Stop identical Ie4hhW
FileAccessI fileAccessI = null; //File Access interface ^pe{b9c
`zE}1M%y
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kJ-*fe'S
{ D*YM[sN`
this.sURL = sURL; r?*NhLG;
this.nStartPos = nStart; S-'fS2
this.nEndPos = nEnd; LbZ:&/t^y8
nThreadID = id; BYo/57&:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qg}O/K
} $LLA,?;!
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\;mH(-
public void run() DANw1_X\
{ `UQf2o0%3w
while(nStartPos < nEndPos && !bStop) *s>BG1$<
{ ,57`D'
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=l0Jb#d
try{ m~D&gGFt
URL url = new URL(sURL); sqS=qC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bgK<pi)d
httpConnection.setRequestProperty("User-Agent","NetFox"); &09U@uc$
String sProperty = "bytes="+nStartPos+"-"; 6"D/xV3Z
httpConnection.setRequestProperty("RANGE",sProperty); -#Z bR
Utility.log(sProperty); j$TwL;
ph#tgLJ
>N?2""
InputStream input = httpConnection.getInputStream(); A?oXqb
//logResponseHead(httpConnection); ( &frUQm
]Bm>-*@0N
h#hxOVl%x
byte[] b = new byte[1024]; 2AVa(
int nRead; &V<W>Y>|l*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >"@?ir
{ bI y sl
nStartPos += fileAccessI.write(b,0,nRead); C(id=F
//if(nThreadID == 1) \6 93kQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B=@ jWz"
} Dr~=o%
f(eQ+0D
gn{=%`[
Utility.log("Thread " + nThreadID + " is over!"); 7lo|dg80
bDownOver = true; 6y5A"-
//nPos = fileAccessI.write (b,0,nRead); Jz!Z2c
} z 8*8OWM
catch(Exception e){e.printStackTrace ();} KHDZ
} :vL1}H<
} A~dQ\M
)*5G">))p
Do]*JO)(
//打印回应的头信息 yt+}K)Hz
public void logResponseHead(HttpURLConnection con) &|<xqt
{ NA.1QQ;e
for(int i=1;;i++) f):~8_0b
{ ZCg`z
String header=con.getHeaderFieldKey(i); 3},Zlu
if(header!=null) I=Oy-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e2C<PGUUB
Utility.log(header+" : "+con.getHeaderField(header)); /"ymZI!k\
else mga6[E<
break; cMzkL%
} <g9"Cr`
} w^1Fi8+
IF@HzT;Q
QI_59f>
public void splitterStop() ?_`0G/xl
{ 'ho{eR@d
bStop = true; ap}5ElMR
} PVao
r Db>&s3
qXXGF_Q
} ;:m&#YJV
=raA?Bp3;(
d/7lefF
/* IwpbfZ
**FileAccess.java X-B8MoG|
*//文件访问(定位，写) <SVmOmJ-K
package NetFox; yW.COWL=)
import java.io.*; 1'G8o=~
Vj; vo`T
*T4<&
public class FileAccessI implements Serializable{ +ySY>`1k~
Pj7gGf6v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W>spz~w%j
RandomAccessFile oSavedFile; !ax;5@J
long nPos; }iIbcA
J -Qh/d%]
oj}"H>tTp
public FileAccessI() throws IOException /'y5SlE[J
{ v@G4G*x\
this("",0); G5Q!L;3HZ
} {aN(d3c
MY-.t-3
W'_/6_c$!
public FileAccessI(String sName,long nPos) throws IOException ;Mj002.\G
{ {@M14)-x>_
oSavedFile = new RandomAccessFile(sName,"rw"); 9u wL{P&
this.nPos = nPos; t ,qul4y}
oSavedFile.seek(nPos); xKp0r1}
} MB:n~>ga
.R5/8VuHF
w1B<0'#
public synchronized int write(byte[] b,int nStart,int nLen) SNvb1&
{ ~q%
int n = -1; Jm![W8L
try{ 2 X<nn
oSavedFile.write(b,nStart,nLen); xaXV^ZM3
n = nLen; eX<K5K.B
} p[YWSjf
catch(IOException e) I$N7pobh
{ TC-f%1(
e.printStackTrace (); =|y|P80w
} g'G8 3F
A9BxwQU#
>rwYDT#m]
return n; MOV =n75
} *5wv%-
Pi%tsKk%
96W4c]NT
} gStY8Z!k
f-vK}'Z`,
",ad7Y7i
/* silp<13HN
**SiteInfoBean.java EHWv3sR-
*/ R+^zy"~
package NetFox; K%<GU1]-]
#5d8?n
bD@@tGr;W
public class SiteInfoBean { h]C2 8=N
W}k[slqZA
RQ5P}A 3H
private String sSiteURL; //Site's URL j@g!R!7)
private String sFilePath; //Saved File's Path Qrz*Lvle h
private String sFileName; //Saved File's Name ]1Qi=2'
private int nSplitter; //Count of Splited Downloading File q+J0}y{#8)
t!savp
5|m9:Hv[#
public SiteInfoBean() </hR!Sb]
{//nSplitter的缺省值为5 >;.*
//default value of nSplitter is 5 h~.V[o7=
this("","","",5); A xR\ned
} F$C+R&V_
573~-Jvx
&0h=4i=6r
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Wlxk
{ 'w`d$c/p
sSiteURL= sURL; _6/Qp`s
sFilePath = sPath; k#-[ M.i
sFileName = sName; :`j"Sj!t3
this.nSplitter = nSpiltter; mlmnkgl ]
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tdb4?^.s
} #m_\1&g
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b__n~\q_
public String getSSiteURL() R3cG<MjmK
{ `C ?a
return sSiteURL; 3dY6;/s
} C!I\Gh
fVv$K&
r}Q@VS%%
public void setSSiteURL(String value) g<;Nio
{ q w"e0q%)
sSiteURL = value; w`"W3(
} vatx+)
M!{Rq1M
l!Nvn$hm
public String getSFilePath() wN$uX#W|
{ .Pqj6Ko9
return sFilePath; oF`-cyj"
} pq@$&G
>E{#HPpBi
"P9wT)J_
public void setSFilePath(String value) Pm'.,?"
{ FP0<-9DO
sFilePath = value; \"{/yjO|4
} X/K| WOO6
d8 3+6d
T9,lblUQ
public String getSFileName() Uia)5zz8
{ `,<>){c|
return sFileName; cC*zj\O
} R?i-"JhW
oo"JMD)
hnlU,p&y3
public void setSFileName(String value) FC|y'j 0
{ IiQWs1
sFileName = value; L+`}euu5
} WllCcD1
$=QNGC2+
<L[ *hp
public int getNSplitter() Fvcq^uZ
{ ;L MEU_
return nSplitter; xX[{E x
} M}{n6T6B
Q|zE@nLS
P<g|y4h
public void setNSplitter(int nCount) [7CH(o1a&
{ Bil;@,Z#
nSplitter = nCount; $]`'Mi
} (W{rv6cq
} _j|n}7a
SvCK;$:
F\YcSDM
/* FeincZ!M
**Utility.java QB oZCLv
*/ 3w6JV+?
package NetFox; P,LXZ
3L\s8O
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public class Utility { kKI!B`j=
!F}J+N=}
8EVF<@{]
public Utility() K{7S
{ #RZJ1uL
4jue_jsle
B "s8i{Vm
} hBs>2u|z9
:9O0?6:B|
//线程睡眠 S]e~)IgO
public static void sleep(int nSecond) :@z5& h
{ (J?}eb;>n
try{ U+3PqWB
Thread.sleep(nSecond); jd*%.FDi{
} PSrt/y!
catch(Exception e) &t=>:C$1Y
{ j#.-MfB
e.printStackTrace (); K:Xrfn{s
} `Mh<S+/
} c`N`xU+z
-EX3' [*'
//日志 ezNE9g
public static void log(String sMsg) R4J>M@-0v
{ h-v&I>
System.err.println(sMsg); &#EVE xL
} 'c+qBSDA
9@&Z`b_
}'M1(W
public static void log(int sMsg) _bV=G#qKK
{ H ]N/Y{
System.err.println(sMsg); s }R:q
} *R~(:z>>
} x /Ky: Ky
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2g07wJ6x
/* Wg;TXs/
**TestMethod.java N55=&-p
*/ Q*J ~wuE2
package NetFox; ~!+h"%'t
5FR#_}k]_F
rp[oH=&
public class TestMethod { ,Vn]Ft?n
r.G/f{=<@
})u}PQ
public TestMethod() %D6Wlf+^n
{ ///xx/weblogic60b2_win.exe Vv"wf;#
try{ u0H`%m
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7JwWM2N?V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %T*+t"\)
SiteFileFetch fileFetch = new SiteFileFetch(bean); bb_jD^
fileFetch.start(); u2\qg;dP
} !'t2
catch(Exception e){e.printStackTrace ();} KI QBY!N+
:XY3TI
nv[Sb%/
} cj_?*
e.YchGTQ
{3uSg)
public static void main(String[] args) _89G2)U=C
{ Zdg{{|mm
new TestMethod(); s!!t
} iiDkk
} nMvIL2:3
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