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)); rh;@|/<l
} n<C4-'^U[a
for(int i=0;i<nEndPos.length-1;i++) #lA8yWxr
{ &w{""'
nEndPos = nStartPos[i+1]; XqD/~_z;
} }*+?1kv
nEndPos[nEndPos.length-1] = nFileLength; 'BE &lW
} {Vz.| a[T
} I?sA)!8
2{t i])
U1&pcwP
//启动子线程 J\iyc,M<M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mp2J|!Lx
for(int i=0;i<nStartPos.length;i++) eT??F
{ vB0O3]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'qRK6}"T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >UTAk
nStartPos,nEndPos,i); @^Tof5?F?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l#8SlRji
fileSplitterFetch.start(); tz(\|0WDQ
} !2dA8b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u(ep$>[F#_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]lj,GD)c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9Vp|a&Ana
nEndPos = " + nFileLength); vfG4PJ 6
// fileSplitterFetch[nPos.length-1].start(); _C`cO
F<8Rr#Z
Ax[!7~s
//等待子线程结束 Vmj7`w&
//int count = 0; %j],6wW5J
//是否结束while循环 L%,tc~)A
boolean breakWhile = false; $+` YP
RhM]OJd'
oXA3i
while(!bStop) |1d;0*HIgX
{ v?b9TE
write_nPos(); ,o(7z^1Pe;
Utility.sleep(500); kz]vXJ
breakWhile = true; z@E-pYV
Pkx*1.uo
57/9i> @
for(int i=0;i<nStartPos.length;i++) x\qS|q\N
{ G([8Q8B4+
if(!fileSplitterFetch.bDownOver) _D9`L&X}
{ ^4@~\#$z
breakWhile = false; vywd&7gK
break; Do@:|n
} \VL[,z=q.
} i~\fpay
if(breakWhile) -uZ bVd
break; +QNFu){G
$~UQKv>
AJ-p|[wPz
//count++; "kC uCc
//if(count>4) |*079v
// siteStop(); [t55Kz*cD
} 5ru&In&
C2GF N1i
I8r5u=PH
System.err.println("文件下载结束！"); s^KUe%am0
} HC,YmO:df"
catch(Exception e){e.printStackTrace ();} 1 h(oty2p
} uWw4l"RK`
Skgvnmk[U
+5pK[%k
//获得文件长度 TK.a6HJG
public long getFileSize() (fON\)l
{ [;M31b3
int nFileLength = -1; d%l_:M3
try{ nenYP0
URL url = new URL(siteInfoBean.getSSiteURL()); 2`(-l{3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q1j<p)(
httpConnection.setRequestProperty("User-Agent","NetFox"); /1-
jbQ2G|:Q
%MyA;{-F6
int responseCode=httpConnection.getResponseCode(); @MIBW)P<
if(responseCode>=400) jRN*W2]V
{ 0raVC=[
processErrorCode(responseCode); UkrqHHpy
return -2; //-2 represent access is error ]_NN,m>z
} "oZ]/(
%FnaS u
m%ZJp7C
String sHeader; J_tj9+r^
&.ZW1TxE8
1aKYxjYM
for(int i=1;;i++) }5gAxR,
{ )5Yv7x(K
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sGIY\%
//Utility.log(in.readLine()); TQm x$
sHeader=httpConnection.getHeaderFieldKey(i); "Y@rNmBj
if(sHeader!=null) &Im{p7gf!b
{ ")|3ZB7>*
if(sHeader.equals("Content-Length")) WrhC q6
{ +}c '4hRv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4,L(
break; IVD1mk
} Q!/<=95E
} xlVQ[Mt
else Eq-fR~<9
break; grEmp9Q ?
} <{@?c
} MdK!Y
catch(IOException e){e.printStackTrace ();} .J' 8d"+
catch(Exception e){e.printStackTrace ();} 4?XX_=+F|
c^P8)gPf
_[8xq:G
Utility.log(nFileLength); 87%t=X
P9Hv){z
^_b+o
return nFileLength; .#R\t 7m%
} 8[i#x|`g
vQ=W<>1
\a+F/I$hwa
//保存下载信息（文件指针位置） DX.u"&Mm
private void write_nPos() F\!;}z
{ =W)Fa6P3j(
try{ hGi"=Oud2
output = new DataOutputStream(new FileOutputStream(tmpFile)); ay6G1\0W
output.writeInt(nStartPos.length); CBx1.xL
for(int i=0;i<nStartPos.length;i++) H=]$9ZH!
{ >nmby|XtW
// output.writeLong(nPos); E",s]
output.writeLong(fileSplitterFetch.nStartPos); 5)4*J.
output.writeLong(fileSplitterFetch.nEndPos); *leQd^47
} 3/8o)9f.
output.close(); DQW^;Ls
} 6Uq@v8mh
catch(IOException e){e.printStackTrace ();} quc?]rb
catch(Exception e){e.printStackTrace ();} vPEL'mw/3#
} 9Ue3 %?~c
1 GUF,A+_O
f XxdOn.
//读取保存的下载信息（文件指针位置） sKIWr{D
private void read_nPos() b?7?iV4
{ uy\<t
try{ T/G1v;]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); P\;lH"9
int nCount = input.readInt(); B&A4-w v
nStartPos = new long[nCount]; Mt)~:V+:
nEndPos = new long[nCount]; 8'J>@ uW
for(int i=0;i<nStartPos.length;i++) Wq 7 c/|
{ & Sy0Of
nStartPos = input.readLong(); rb%P30qc4
nEndPos = input.readLong(); 3:jKuOX
} A<^IG+Q,B7
input.close(); %Rv&VFg
} BDZB;DPb
catch(IOException e){e.printStackTrace ();} y %Get
catch(Exception e){e.printStackTrace ();} W>eJGZ<
} b_-ESs]g
ju8tNL,J
# 'G/&&<
private void processErrorCode(int nErrorCode) Z@&_ T3M
{ rz+G]J
System.err.println("Error Code : " + nErrorCode); aB<~T[H%h
} B, nCx=\S
x3>K{
CF9a~^+%
//停止文件下载 dluNA(Xc-
public void siteStop() T8>:@EL-k
{ Fh& `v0
bStop = true; `g6XVa*%#
for(int i=0;i<nStartPos.length;i++) w[\*\'Vm0
fileSplitterFetch.splitterStop(); wl^bvHG
4XK*sR0-`
&Wfs6g
} t3u"2B7oG
} bO1J#bcZ
//负责部分文件的抓取 'p-jMD}O
**FileSplitterFetch.java dgpo4'c}
*/ I<|)uK7
package NetFox; r<V]MwO=
> C{^{?~u
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import java.io.*; x*}j$n(Oa
import java.net.*; `x$d8(1J`#
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xc Wr hg
public class FileSplitterFetch extends Thread { M_+&XLnzsJ
aq~hl7MTj
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String sURL; //File URL hXM8`iFW5
long nStartPos; //File Snippet Start Position -h^FSW($-R
long nEndPos; //File Snippet End Position )v;>6(
int nThreadID; //Thread's ID ('Wo#3b$
boolean bDownOver = false; //Downing is over w_pEup\`
boolean bStop = false; //Stop identical 4>>{}c!nf
FileAccessI fileAccessI = null; //File Access interface F6h3M~uR
*c7kB}/
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @=`Dw/13
{ ,0NVb7F;k
this.sURL = sURL; rZ 9bz}K
this.nStartPos = nStart; 2\l7=9 ]\3
this.nEndPos = nEnd; Z"'rc.>a
nThreadID = id; [VIdw92
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^"v~hjM#
} ,)'!E^n
pSkP8' ?
-(~Tu>KaH
public void run() 5^cPG" 4@
{ !I]fNTv<
while(nStartPos < nEndPos && !bStop) W=}l=o!G.
{ p.TR1BHw
5p"n g8nR
xr?=gY3E;
try{ u$[ '}z0:
URL url = new URL(sURL); GZ/.eYE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0vmMNF
httpConnection.setRequestProperty("User-Agent","NetFox"); cy*Td7)/
String sProperty = "bytes="+nStartPos+"-"; >Mj :'
httpConnection.setRequestProperty("RANGE",sProperty); ur={+0 y
Utility.log(sProperty); 1c&/&6#5
y;Q_8|,F
/:>qhRFJA:
InputStream input = httpConnection.getInputStream(); U`K5 DZ~
//logResponseHead(httpConnection); uzG<(Q pu
1c~c_Cc4
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byte[] b = new byte[1024]; SEXeK2v
int nRead; O7ceSz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [Av87!kJ!X
{ J)A1`(x&T
nStartPos += fileAccessI.write(b,0,nRead); 'e02rqip{
//if(nThreadID == 1) 78#je=MDg
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #6fp"
} !FipKX
U4%d#
GBu&2}
Utility.log("Thread " + nThreadID + " is over!"); \:4WbM:B
bDownOver = true; %\\l/{`eW
//nPos = fileAccessI.write (b,0,nRead); E}c(4RY
} c.m '%4
catch(Exception e){e.printStackTrace ();} +`kfcA#pi
} {5-4^|!
} zCL/^^#
[%YA42_`LD
yeKzI~
//打印回应的头信息 T9KzVxHp5
public void logResponseHead(HttpURLConnection con) '[I_Iu#,
{ 8HX(1nNj}
for(int i=1;;i++) )+wBS3BC
{ [|d:QFx
String header=con.getHeaderFieldKey(i); wblEx/FqE^
if(header!=null) "@W0Lk[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gsI"G
Utility.log(header+" : "+con.getHeaderField(header)); }XaO~]
else 1d7oR`qr
break; PP/M-Jql)
} AnU,2[(
} gQ.yNe
~ 61?nu
jU)r~QhN
public void splitterStop() _zI95
{ Fj"gCBaR
bStop = true; Y4){{bEp
} A|CW4f,
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$6XSW
} "w9`UFu%^e
%lbSV}V)
IKKd
/* L-^vlP)Vu
**FileAccess.java 3^q,'!PfB
*//文件访问(定位，写) yX$I<L<Suz
package NetFox; %CfJ.;BDNE
import java.io.*; { >{|3
6LL/wemq
gHQ[D|zu
public class FileAccessI implements Serializable{ v#a`*^ ^
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//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Zn1+} Z@I
RandomAccessFile oSavedFile; .6xP>!E}Q
long nPos; ,E3"AisI
{r`l
zwN;CD1
public FileAccessI() throws IOException \U4O*lq
{ VmF?8Vi4
this("",0); 6b9Ddb*
} JHwkLAuz
&1%W-&bc6
'j !!h4
public FileAccessI(String sName,long nPos) throws IOException sDK lbb
{ -. L)-%wIV
oSavedFile = new RandomAccessFile(sName,"rw"); N$M#3Y;
this.nPos = nPos; Z%D*2wm4
oSavedFile.seek(nPos); Z_}vjk~s
} 7e/Uc!&*
>J[g)$,
-\6tVF11z
public synchronized int write(byte[] b,int nStart,int nLen) Ht5 %fcD
{ ?1?^>M
int n = -1; j.uN`cU!
try{ -i V&-oP
oSavedFile.write(b,nStart,nLen); }el.qZ
n = nLen; e7t).s)b{
} +[UFf3(ON
catch(IOException e) wA+J49
{ @4B+<,i
e.printStackTrace (); VW<s_
} !X(Lvt/
9.qIhg
>>rW-&
return n; ?t'ZX~k
} 3q R@$pm
Lt8chNi [
XASoS5
} lJi'%bOi
4-eb&
-9~kp'_a
/* L5(rP\B
**SiteInfoBean.java 'jZ2^
*/ v!E0/ gD
package NetFox; _J6|ju\
HelC_%#^
c ^G\w+_
public class SiteInfoBean { .6!IO^`[
&0K;Vr~D
<&n3"
private String sSiteURL; //Site's URL U u(ysN4`
private String sFilePath; //Saved File's Path K$\az%NE
private String sFileName; //Saved File's Name LG [2u
private int nSplitter; //Count of Splited Downloading File ;9q3FuR
YPDc /
?1xBhKq
public SiteInfoBean() 6TbDno/!'
{//nSplitter的缺省值为5 F@kOj*5,[
//default value of nSplitter is 5 U#ueG
this("","","",5); d@b0z$<s
} tE]g*]o
,ZJI]Q=!
COOazXtW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?g}n$%*5y!
{ @zEEX9U
sSiteURL= sURL; _{8f^@I"+
sFilePath = sPath; JS642T
sFileName = sName; u'd+:uH
this.nSplitter = nSpiltter; |b;}' *
Q nDymVF
q =b.!AZy
} !aeL*`;
;wbQTp2
z tHGY
public String getSSiteURL() ibl^A=
{ }H?8~S=
return sSiteURL; HPCzh
} { Y|h;@j$
oB-&ma[ZS
pco~Z{n
public void setSSiteURL(String value) Xl#vVyO
{ 1(gb-u0
sSiteURL = value; %/oOM\}++
} t^Aios~F
Fla[YWS
[@";\C_I
public String getSFilePath() N;F1Z-9
{ -3qB,KT
return sFilePath; J{@gp,&e
} PkLRQ}
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public void setSFilePath(String value) P~#!-9?
{ =3{h9
sFilePath = value; ~4U[p 50
} '# "Z$
C:hfI;*7
>L$y|8O
public String getSFileName() s^^X.z ,
{ 5w gtc~
return sFileName; +#6WORH0S
} Umm_FEU#]
%bt2^
R# 8D}5[&
public void setSFileName(String value) e=%7tK*
{ (gNI6;P;}
sFileName = value; %\}|&z6
} w(J-[t118
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zek\AQN
public int getNSplitter() OZbwquF@
{ elWN-~
return nSplitter; )"m FlS<I
} enF.}fo]
Z"lL=0rY/
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public void setNSplitter(int nCount) B+jT|Y'
{ .!U `,)I
nSplitter = nCount; XU2HWa
} nOkX:5
} !}"npUgE
]b'K BAMy
iEr|?,
/* ;G0~f9
**Utility.java 5BS-q"
*/ <.l5>mgkCw
package NetFox; Y3-Tg~/~W
eoR@5OA&
C]WVH\Pp
public class Utility { ,'Y*e[
N,(@k[uta
|E53 [:p
public Utility() !H~!i.m'-
{ u7^Z7; J
2N5N^S
D?}LKs[
} HNY{%D
r;y&Wa
//线程睡眠 jS5e"LMIq
public static void sleep(int nSecond) (+Gd)iO
{ N?kXATB
try{ c[sC 2
Thread.sleep(nSecond); b[uTt'p}
} UldKlQ8
catch(Exception e) vW"x)~B
{ }C/}8<
e.printStackTrace (); plsf` a
} V3yO_Iqa
} D@[$?^H
x)BG%{h
//日志 dWR?1sV|e
public static void log(String sMsg) n-Dr/c4
{ 1Lqs>*
System.err.println(sMsg); 6:v8J1G(<
} i/C#fIB2
QDBptI:
bTA<AoW9="
public static void log(int sMsg) aMm`G}9n
{ &4O"Xs`ka
System.err.println(sMsg); OMJr.u
} ] X%bU*4
} _]j=[|q 9
cn<9!2a
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/* 4yQ4lU,r
**TestMethod.java W;~^3Hz6
*/ GY@Np^>[a
package NetFox; 9rn!U2
@F=ZGmq
8}xU]N#EV
public class TestMethod { EIEwrC
{4}Sl^kn*
V *S|Qy!p
public TestMethod() @a%,0Wn
{ ///xx/weblogic60b2_win.exe [DGq{(O
try{ A"vI6ud>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); - CM;sXq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Qyt6+xL
SiteFileFetch fileFetch = new SiteFileFetch(bean); P/nXY
fileFetch.start(); Sl:\5]'yJ
} -/#3U{O
catch(Exception e){e.printStackTrace ();} b'3#FI=:
qbqJ1^!6R
8 Sl[&
} 0<nKB}9
/RX7AXXB
(C6Y*Zm\
public static void main(String[] args) xS,):R
{ d@C ;rzR
new TestMethod(); ZJy D/9y
} dH?pQ
} uBl&|yvxB
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