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)); 8Hf:yG,
} .$rt>u,8<
for(int i=0;i<nEndPos.length-1;i++) (oUh:w.]Gw
{ |([|F|"
nEndPos = nStartPos[i+1]; B5pWSS
} 8+?|4'\`
nEndPos[nEndPos.length-1] = nFileLength; >U.f`24
} w]%|^:
} /'ukeK+'
G2,9$8qE
H2cY},
//启动子线程 q_R^Q>ZIe
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8iIz!l%O
for(int i=0;i<nStartPos.length;i++) k>'c4ay290
{ 4D4Y.g_x
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ` 465 H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2JMMNpya
nStartPos,nEndPos,i); /_?y]Ly[r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1p|h\H
fileSplitterFetch.start(); (H_YYZ3ZX
} B=R9K3f
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0wA?.~ L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b.4H4LV
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {'^!S"9x
nEndPos = " + nFileLength); K,$Ro@!
// fileSplitterFetch[nPos.length-1].start(); Wifr%&t{J
2H]~X9,z2
HTa]T'
//等待子线程结束 PdkS3Hz
//int count = 0; iVQ)hsW/
//是否结束while循环 *=KX0%3
boolean breakWhile = false; G|LJOq7QB
hk7kg/"
pAm L
while(!bStop) E[nJ'h<h
{ Tp.t.Qic
write_nPos(); 5?yc*mOZ
Utility.sleep(500); F s{}bQyQ
breakWhile = true; &3:U&}I
%"C%pA
;r1.Uz(
for(int i=0;i<nStartPos.length;i++) ]i@WZ(
{ kzb%=EI
if(!fileSplitterFetch.bDownOver) ^=1:!'*3D
{ }23#z
breakWhile = false; -!s?d5k")
break; WS7a]~3'
} 4b}94e@(N
} S*D Bzl
if(breakWhile) y?}R,5k
break; / Ml d.
5{.g~3"
"(QI7:iM
//count++; tnn,lWu|
//if(count>4) zNo(|;19
// siteStop(); 'y? HF@NJ
} KsG>,# Q
sZ7RiH+I
/BaXWrd+
System.err.println("文件下载结束！"); {<k}U;uiO
} p&O-]o8
catch(Exception e){e.printStackTrace ();} [? 1m6u;
} YZHqy++x
/yd<+on^
x$WdW+glZ-
//获得文件长度 J=OWXL!<a
public long getFileSize() 6tDCaB
{ @:M?Re`L
int nFileLength = -1; F VVpyB|
try{ '-?t^@
URL url = new URL(siteInfoBean.getSSiteURL()); q@6Je(H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yrgb6)]nm@
httpConnection.setRequestProperty("User-Agent","NetFox"); HEMq4v4
.15^c+j
QN'v]z
int responseCode=httpConnection.getResponseCode(); ZBf9Upg
if(responseCode>=400) *9?T?S|^$F
{ (F.vVldBy
processErrorCode(responseCode); jaOt"iU.B
return -2; //-2 represent access is error $(PWN6{\r^
} zB@@Gs>
OpT0V]k^"9
XY*KWO
String sHeader; V!3.MQM
=#Qm D=
a#NP69
for(int i=1;;i++) Jemb0Qv
{ Z^?YTykH
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~p'DPg4
//Utility.log(in.readLine()); S^/:O.X)c,
sHeader=httpConnection.getHeaderFieldKey(i); Z9+xB"q2
if(sHeader!=null) h=`1sfz
{ UZqQ|3
if(sHeader.equals("Content-Length")) : ~R:[T2P
{ y9@DlK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,x.2kb
break; 8g!C'5
} ]B'H(o R<|
} yS2[V,vS7
else SB<09|2
break; <e%~K4KH
} H5'Le{
} ?\J.Tv$$$
catch(IOException e){e.printStackTrace ();} Pqc+pE
catch(Exception e){e.printStackTrace ();} ;[[GA0
(9X>E+0E
`;OEdeAM
Utility.log(nFileLength); _hy<11S;
O:>9yZhV
x.:k0;%Q
return nFileLength; R{hq1-
} |!=KLJUA
Jc74A=sT
U if61)+!i
//保存下载信息（文件指针位置） Q x]zz4jD
private void write_nPos() dreEes`|
{ 6?X)'
try{ ue~?xmZg
output = new DataOutputStream(new FileOutputStream(tmpFile)); Jjgy;*hM
output.writeInt(nStartPos.length); x(UOt;
for(int i=0;i<nStartPos.length;i++) J91O$szA
{ M^$liS.D
// output.writeLong(nPos); w' gKE'c
output.writeLong(fileSplitterFetch.nStartPos); ~l=Jx*
output.writeLong(fileSplitterFetch.nEndPos); |##rs
} _?IP}}jA:
output.close(); )ZP-t!).G#
} >aaHN1Ca
catch(IOException e){e.printStackTrace ();} i H^Gv*
catch(Exception e){e.printStackTrace ();} HR> X@g<c
} wV,l }Xb-
lW8!_h"G`n
bR*/d-v^
//读取保存的下载信息（文件指针位置） jRv j:H9
private void read_nPos() nYv`{0S+m
{ Oy `2ccQ#
try{ (fYrb#]!y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); a=!I(50
int nCount = input.readInt(); n~wNee
nStartPos = new long[nCount]; L9FijF7
nEndPos = new long[nCount]; R>YDn|cWI
for(int i=0;i<nStartPos.length;i++) \B<A.,i4
{ .eSMI!Y=
nStartPos = input.readLong(); nU6WT|
nEndPos = input.readLong(); @}^eyS$|!
} f/VrenZ_
input.close(); dLtn,qCX0^
} "Y7 ]t:8
catch(IOException e){e.printStackTrace ();} Q.N, Q`P
catch(Exception e){e.printStackTrace ();} YVEin1]
} f4k\hUA
c_33.i"I}
UQ ~7,D`=#
private void processErrorCode(int nErrorCode) u,rieKYF
{ o.Jq1$)~y
System.err.println("Error Code : " + nErrorCode); 6a=Y_fma
} I'NE>!=Q
w?+v+k\
%j[DG_
//停止文件下载 LT5rLdn
public void siteStop() Yom,{;Bv
{ MDo4{7
bStop = true; #1v>3H(
for(int i=0;i<nStartPos.length;i++) N]k(8K
fileSplitterFetch.splitterStop(); ^uy2qO4Yw
qU1^ K
&Vtgh3I
} oo:(GfO}
} d/Z258
//负责部分文件的抓取 8w[nY.#T
**FileSplitterFetch.java _Q:739&
*/ qhPvU( ,
package NetFox; V@(7K0
ARZ5r48)
$|2@of.
import java.io.*; "?lm`3W"
import java.net.*; l u^fKQ
9J$8=UuxWG
\:*<En0
public class FileSplitterFetch extends Thread { jmAQ!y|W.
0V:DeX$bZ
B f_oIc
String sURL; //File URL :jFKTG
long nStartPos; //File Snippet Start Position !"dbK'jb^
long nEndPos; //File Snippet End Position SQZUkKfb
int nThreadID; //Thread's ID -%U 15W;
boolean bDownOver = false; //Downing is over % 1+\N
boolean bStop = false; //Stop identical iE|qU_2Y
FileAccessI fileAccessI = null; //File Access interface S!<1CFh
=.]>,N`C
b$24${*'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException sp0j2<$a
{ CFW\
this.sURL = sURL; b83__i
this.nStartPos = nStart; w :w
this.nEndPos = nEnd; +!I7(gL
nThreadID = id; xz+Y1fYT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $=c79Al(
} tp3>aNj
b,U3b})(
M=n_;3,o
public void run() 9\/T #EP
{ @[qGoai
while(nStartPos < nEndPos && !bStop) ,u^S(vxyz
{ V0gk8wD
Ch1+YZG
lD8&*5tDmP
try{ 5PJB<M_m:
URL url = new URL(sURL); &?@gUk74"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yW$ja|^E
httpConnection.setRequestProperty("User-Agent","NetFox"); pX:FXzYQ
String sProperty = "bytes="+nStartPos+"-"; fC_dSM[{c
httpConnection.setRequestProperty("RANGE",sProperty); ERW>G{+
Utility.log(sProperty); 93Yo}6>
2o`a^'Iw
5!55v
InputStream input = httpConnection.getInputStream(); \;?=h
//logResponseHead(httpConnection); H(^O{JC]y!
gDw:Z/1X`
OAc*W<Q0
byte[] b = new byte[1024]; _l&`* 2d
int nRead; 8QeM6;^/5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gzK"'4`
{ VWlOMqL995
nStartPos += fileAccessI.write(b,0,nRead); FTy`#*7Ul
//if(nThreadID == 1) x9#>0 4s
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +$#YW5wy
} '8NKrI
1@nGD<,.
%`%xD>![
Utility.log("Thread " + nThreadID + " is over!"); _jw A_
bDownOver = true; kF9T 9
//nPos = fileAccessI.write (b,0,nRead); ,KlTitJl\+
} |5wuYG
catch(Exception e){e.printStackTrace ();} yJaQcGxE"
} wl{Fx+<^3
} U}xQUFT|
}57wE$9K
e!wS"[,
//打印回应的头信息 E6SGK,f0D
public void logResponseHead(HttpURLConnection con) J~5VL |ca
{ !A"`jc~x:
for(int i=1;;i++) rSIb1zJ
{ 8@)/a
String header=con.getHeaderFieldKey(i); Hp_3BulS<
if(header!=null) ~RVx~hh
//responseHeaders.put(header,httpConnection.getHeaderField(header)); J?XEF@?'G
Utility.log(header+" : "+con.getHeaderField(header)); Ve,_;<F]S
else 1NO<K`
break; C7(kV{h$d
} j:%~:
} @L%9NqE`O
R|T_9/#)
)*@Oz
public void splitterStop() D<[4}og&]
{ \A\a=A[
bStop = true; U9;C#9E
} 5|ih>?C/(
(Al.hEs'
"HW~|M7>(
} pa&*n=&cL
Aa;R_Jz
D-.XSIEMu
/* Ox"4 y
**FileAccess.java ?aInn:FE
*//文件访问(定位，写) +]Oq{v:e
package NetFox; oy!W$ ?6
import java.io.*; m:<cLc :.
:K&
<lM]c
public class FileAccessI implements Serializable{ %-+lud
/vFw5KUu
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _9E7;ew
RandomAccessFile oSavedFile; o/9(+AA>
long nPos; Hw34wQX
Tx35~Z`0
\xk`o5/{
public FileAccessI() throws IOException dL<okw
{ cpB$bC](
this("",0); M:c^[9)y
} WKZ9i2hcdf
`LL#Aia
M_V\mYC8I
public FileAccessI(String sName,long nPos) throws IOException M'D;2qo
{ tFvti5
oSavedFile = new RandomAccessFile(sName,"rw"); :8U=L'4
this.nPos = nPos; 0-EhDGa]r
oSavedFile.seek(nPos); |b'fp1</
} + )?1F
>?yaG=
q('O@-HA
public synchronized int write(byte[] b,int nStart,int nLen) oUEpzv,J
{ 3Juhn5&N
int n = -1; A'qJke=
try{ bL+Hw6;
oSavedFile.write(b,nStart,nLen); 4E:HO\
n = nLen; ]yN]^%PYH
} 5tR<aIf
catch(IOException e) 6a PZW
{ 3|RfX
e.printStackTrace (); )Y@
} \$s<G|<P
FsZF>vaV
$O&P@8:Z
return n; zbP0!
} HE+y1f]
,U2 /J
pL>Q'{7s3
} GiB3.%R`
+L*2 6ar6
<FmrYwt
/* =-{+y(<"r
**SiteInfoBean.java GAbX.9[V
*/ V4f~#Tp
package NetFox; ="3Hc=1?R
BOn2`|oLuF
[#n~ L6
public class SiteInfoBean { r ,|T@|{
:h?"0,
{hK$6bD3^
private String sSiteURL; //Site's URL :*#AJV)
private String sFilePath; //Saved File's Path 2|(J<H
private String sFileName; //Saved File's Name GDP@M)~6*
private int nSplitter; //Count of Splited Downloading File 1=OXi!G
_S/bwPj|~y
"ji4xy
public SiteInfoBean() E=GCq=Uw
{//nSplitter的缺省值为5 JAen=%2b
//default value of nSplitter is 5 W'rft@J$
this("","","",5); wH~Q4)#=o
} ]q7\
or\ 2)
k&ujr:)5Y5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ( }5k"9Z
{ _Qs)~
sSiteURL= sURL; /s uz>o\
sFilePath = sPath; e-H:;m5R
sFileName = sName; 25*/]iu
this.nSplitter = nSpiltter; J`;G9'n2
,ju1:`
8$-Wz:X&
} MOP %vS
P~iu|j
PX52a[wNDH
public String getSSiteURL() "EF:+gi#"
{ A1Mr
return sSiteURL; Jz 'm&mu
} %I;ej{*c
eI; %/6#
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public void setSSiteURL(String value) $ w:QJ~,s
{ #z-6mRB
sSiteURL = value; Fe%Q8RIh_
} `,tv&siSA
R*/%+
#JeZA0r5
public String getSFilePath() oHB51< }
{ `;*%5WD%
return sFilePath; yPn5l/pDDr
} u2y?WcMv
S%-L!V ,
-7TT6+H)
public void setSFilePath(String value) lMB^/-Y
{ {HNGohZt
sFilePath = value; ["Ep.7=SU
} 6GMQgTY^
CspY+%3$
Erl"X}P
public String getSFileName() nsij;C
{ i*..]!7e
return sFileName; E {4/$}
} }&d]Uv/4
nBjfR2TuF
[G+M94[A
public void setSFileName(String value) 7&/iuP$.
{ }7+G'=XI/
sFileName = value; HviL4iO
} x&+/da-E/5
Nj*J~&6G
zGj0'!!-
public int getNSplitter() Uc!}D
{ O1Ey{2Q
return nSplitter; mWsVOf>g
} [IF3,C
'{QbjG%<P
4Wk/^*?
public void setNSplitter(int nCount) #q9jFW8
{ zPWG^
nSplitter = nCount; >1T=Aw2Z.
} C]K@SN$
} 2TmQaDu%b
])'22sY
2Prr:k
/* D@!`b6
**Utility.java 0diQfu)Fi
*/ ;XSV}eLu
package NetFox; ?lnX."eAdB
us"SM\X#
uNxR#S
public class Utility { xV}E3Yj2#
!3v!BJ#+,&
}?$d~]t)
public Utility() epJVs0W
{ K;,n?Q w
+IK~a9t
7]@vPr;:
} y'*^ '
A/lxXy}D
//线程睡眠 [53rSr
public static void sleep(int nSecond) 4M*UVdJ;
{ b|u4h9
try{ I{;s.2
Thread.sleep(nSecond); vK!,vKa.
} F/tBr%RV
catch(Exception e) 4gG&u33RrE
{ GQ[:vX`
e.printStackTrace (); 36@)a5
} 25XD fi75
} I5wf|wB-
|t1D8){!
//日志 ~=aGv%vX
public static void log(String sMsg) Q 6{2@
{ eA$9)K1GO
System.err.println(sMsg); J~V`"uo
} e57}.pF^
IfF<8~~E
3:&!Q*i;
public static void log(int sMsg) yP :>vFd7
{ ~!E%GCyFy
System.err.println(sMsg); 6c^2Nl8e
} H|tbwU)J
} z `T<g!Y
&1ASWllD
2/PaXI/Z
/* ~j^HDHY@
**TestMethod.java T|GRkxd,E3
*/ [(BA:x1
package NetFox; Nj1vB;4Nx
WpP8J1KN[
8b8ui
public class TestMethod { K I
Fx~=mYU
cR 4xy26s
public TestMethod() z'O$[6m6
{ ///xx/weblogic60b2_win.exe ,+3l9FuQ
try{ KRd.Ubs -
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;El"dqH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); M}!7/8HUC
SiteFileFetch fileFetch = new SiteFileFetch(bean); W#$ pt>h)
fileFetch.start(); -\b~R7VQ
} YT+fOndjaF
catch(Exception e){e.printStackTrace ();} UO5^4
,}2M'DSWa
IxAKIa[HY
} 36`aG Y
^2mmgN
K 4j'e6
public static void main(String[] args) bmr.EB/
{ L7el5Q!Y=
new TestMethod(); U;Se'*5xv
} HDvj{
} t/yGMR=
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