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)); b6M)qt9R
} ill'KPy
for(int i=0;i<nEndPos.length-1;i++) %iFIY=W
{ T{xo_u{Q
nEndPos = nStartPos[i+1]; 0 9'o
} (zODV4,5k`
nEndPos[nEndPos.length-1] = nFileLength; |y=F (6Z
} ba:^zO^
} %SFR.U0}yK
wq`Kyhk
s|`)'
//启动子线程 1ORi]`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q"_T040B
for(int i=0;i<nStartPos.length;i++) ,'DrFlI
{ 6y!?xot
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X(q=,^Mp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~a,'
nStartPos,nEndPos,i); W 9MZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m&c(N
fileSplitterFetch.start(); Olh-(u:9+O
} mK&9p{4#U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6HQwL\r79
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); p%_ :(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nezbmpL4
nEndPos = " + nFileLength); yp'>+cLa
// fileSplitterFetch[nPos.length-1].start(); 6u3(G j@
>x0lSL0y
epyYo&x}
//等待子线程结束 m)w-mc
//int count = 0; qnV9TeU)
//是否结束while循环 >5W"a?(
boolean breakWhile = false; L 'Rapu
y{P9k8v!z
BkqW>[\5xm
while(!bStop) ]a~LA7VHO
{ )f&]H}
write_nPos(); 70(?X/5#
Utility.sleep(500); Av4E?@R
breakWhile = true; OEi9 )I
Qj[O$L0 $
4'|:SyOm
for(int i=0;i<nStartPos.length;i++) 5W-M8dc6
{ ;itg>\p3
if(!fileSplitterFetch.bDownOver) rmJ847%y`
{ <Wq{ V;$
breakWhile = false; /hR]aw
break; o:*iT=l
} ixpG[8s
} mSeNM
if(breakWhile) 2 -8:qmP(
break; fbkjK`_q
"b7C0NE
{Oszq(A
//count++; >:|q J$J.
//if(count>4) Q(7l<z
// siteStop(); _3>zi.J/
} zjE4v-H:l
=LA@E&,j
#E)]7!_XG
System.err.println("文件下载结束！"); fdHxrH>*
} y5h[^K3
catch(Exception e){e.printStackTrace ();} oPZ4}>uV
} LRs;>O
>*CK@"o
F x8)jBB_
//获得文件长度 ^2@~AD`&h
public long getFileSize() (Ad!hyE(
{ JFdzA
int nFileLength = -1; [)u{-
try{ I%xJ)fIK
URL url = new URL(siteInfoBean.getSSiteURL()); IBsn>*ja<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z_+No :F7I
httpConnection.setRequestProperty("User-Agent","NetFox"); `^{P,N>X
4/_|Qy
$Bb/GXn{\
int responseCode=httpConnection.getResponseCode(); (DAJ(r~
if(responseCode>=400) 4f,x@:Jw
{ PCjY,O
processErrorCode(responseCode); EV$n>.
return -2; //-2 represent access is error "KwKO8f
} GrC")Z|3u
}C}_ I:=C
UlytxWkUX
String sHeader; w7u >|x!
`$- Ib^
ZZ7U^#RT
for(int i=1;;i++) d5hE!=
{ =<xbE;,0
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k=_@1b-
//Utility.log(in.readLine()); W -&5 v
sHeader=httpConnection.getHeaderFieldKey(i); z& jDOex
if(sHeader!=null) ~V)E:(
{ ;_\P;s
if(sHeader.equals("Content-Length")) HbVLL`06*
{ V;(LeuDH|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #CmBgxg+M
break; Y1IlH8+0
} O2f2Fb$B7
} o5R40["
else U)8]pUI+/P
break; <X*8Xzmv
} -}o;Y)
} _#B/#^a
catch(IOException e){e.printStackTrace ();} 5;Xrf=
catch(Exception e){e.printStackTrace ();} ;"z>p25=T
wt;aO_l
xkovoTzV
Utility.log(nFileLength); jfamuu7
B?Skw{&
;0'v`ob'.?
return nFileLength; Z ngJ9js
} UepBXt3)
OFv} jT
566Qikw2
//保存下载信息（文件指针位置） )/'s& D
private void write_nPos() HxaUVg0
{ IIkJ"Qg.
try{ y rk#)@/m
output = new DataOutputStream(new FileOutputStream(tmpFile)); flqTx)xE
output.writeInt(nStartPos.length); 5@ug1F&
for(int i=0;i<nStartPos.length;i++) wn&2-m*a
{ X$f%Ss
// output.writeLong(nPos); .EO1{2=
output.writeLong(fileSplitterFetch.nStartPos); )VC) }
output.writeLong(fileSplitterFetch.nEndPos); PQ>JoRs
} T^_9R;
output.close(); nCU4a1rZ
} L_,U*Jyo
catch(IOException e){e.printStackTrace ();} jLSZ#H
catch(Exception e){e.printStackTrace ();} hLRQ)
} Z]<_a)>
<h({+N
L%FL{G
//读取保存的下载信息（文件指针位置） #ZA YP
private void read_nPos() 30@ GFaab
{ ^dqEOW
try{ 9&cZIP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [@6iStRg7
int nCount = input.readInt(); }^muAr
nStartPos = new long[nCount]; e^yB9b
nEndPos = new long[nCount]; jxvVp*-=<j
for(int i=0;i<nStartPos.length;i++) }JD(e}8$!
{ Npqbxb
nStartPos = input.readLong(); %:*HzYf
nEndPos = input.readLong(); ,"o\_{<z
} H^G*5EQK
input.close(); I?QKd@
} /V&Y@j
catch(IOException e){e.printStackTrace ();} kN)ev?pQ[
catch(Exception e){e.printStackTrace ();} ~6tY\6$9f
} e3K
8T4J^6
PJ{.jWwD
private void processErrorCode(int nErrorCode) 7 <xxOY>y
{ |Bp?"8%*l
System.err.println("Error Code : " + nErrorCode); /!hW6u5
} $Tg$FfD6&
;QYK {3R?
q)*0G*
//停止文件下载 ArY'NE\Htt
public void siteStop() '' 6
{ 4rm/+Zes
bStop = true; F~1R.r_Lu
for(int i=0;i<nStartPos.length;i++) scdT/|(U$
fileSplitterFetch.splitterStop(); E_K7.c4M
:R)IaJ6)
DI_mF#5q
} . fIodk
} H|Ems}b
//负责部分文件的抓取 a|.u;
**FileSplitterFetch.java ]l%j>Vb!L
*/ {Fj`'0Xu;
package NetFox; G;e}z&6<k
C1=[\c~jw
(k?OYz]c
import java.io.*; cnR>)9sX
import java.net.*; 5 F-Q&
U:Y?2$#
T1E{NgK
public class FileSplitterFetch extends Thread { L" o6)N
nV,a|V5Xm
;c`B'
String sURL; //File URL `d8TA#|`
long nStartPos; //File Snippet Start Position /y}
long nEndPos; //File Snippet End Position -8IiQRS
int nThreadID; //Thread's ID v,jU9D\
boolean bDownOver = false; //Downing is over <~dN23)
boolean bStop = false; //Stop identical 4P8:aZM
FileAccessI fileAccessI = null; //File Access interface y;;@T X
.eE5pyw+C
$)U RY~;i
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gnQd#`
{ 4t":WutC
this.sURL = sURL; 1 !sYd@iD@
this.nStartPos = nStart; "P6MLf1
this.nEndPos = nEnd; /=N`P &R#
nThreadID = id; <XNLeJdY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y.zW>Mfl
} {}z7N~
@bZb#,n]
PJ'l:IU
public void run() rZLMYM
{ +mJAIjH
while(nStartPos < nEndPos && !bStop) >_@J&vC
{ IoC,\$s,
[K5afnq`
vQ;Z 0_
try{ 4 QWHGh"
URL url = new URL(sURL); [lf[J&}X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m\(a{x
httpConnection.setRequestProperty("User-Agent","NetFox"); w"~T5%p
String sProperty = "bytes="+nStartPos+"-"; zIu1oF4[
httpConnection.setRequestProperty("RANGE",sProperty); H_{Yr+p
Utility.log(sProperty); ,D8Tca\v
FX{Sb"
/O9z-!Jz
InputStream input = httpConnection.getInputStream(); aa|xZ
//logResponseHead(httpConnection); %EuSP0
`!i>fo~
<*L8kNykK
byte[] b = new byte[1024]; K$4Ky&89
int nRead; =_5-z|<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [Mx+t3M
{ p|zW2L
nStartPos += fileAccessI.write(b,0,nRead); s^cHR1^
//if(nThreadID == 1) [8ih-k
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o.,hCg)X
} "zugnim
?n}L+|
c5JxKU_
Utility.log("Thread " + nThreadID + " is over!"); BwR)--75
bDownOver = true; IMj{n.y4
//nPos = fileAccessI.write (b,0,nRead); ;*8$BuD
} .A E(D7d6
catch(Exception e){e.printStackTrace ();} Yv>% 5`
} [,VD^\
} |g~.]2az
xu3qX"
Ra/S46$
//打印回应的头信息 Ta_#Rg*!
public void logResponseHead(HttpURLConnection con) T!8,R{V]4
{ *cf#:5Nl
for(int i=1;;i++) SO|$X
{ Gd!y,n&s
String header=con.getHeaderFieldKey(i); @>:r'Fmu-
if(header!=null) O%OeYO69
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4oJ0,u
Utility.log(header+" : "+con.getHeaderField(header)); tlj^0
else ,a}+Jj{
break; uKK+V6}!kj
} JMXCyDy;
} WawOap
Ls( &.
YM-,L-HMA
public void splitterStop() -Wf 2m6t
{ )<%GHDWL
bStop = true; T{Av[>M
} LBTf}T\
iNcB6,++
06ZyR@.@v
} XLB7 E
)Zox;}WK+
H?PaN)_6-+
/* d-X<+&VZ
**FileAccess.java mk}8Cu4
*//文件访问(定位，写) 1$4dzI()
package NetFox; f mf(5
import java.io.*; n*uT
y6fYNB
s_/CJ6s
public class FileAccessI implements Serializable{ F.4xi+S_
C-&\qAo?<:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i!(u4wTFF
RandomAccessFile oSavedFile; Tv!zqx#E
long nPos; P9BShC5
RK< uAiU
>HyZ~M
public FileAccessI() throws IOException V3 2F
{ $/K<hT_
this("",0); "_W[X
} `ml
U&GSMjqg
p[>!;qI
public FileAccessI(String sName,long nPos) throws IOException `@RTfBBg
{ _->d41
oSavedFile = new RandomAccessFile(sName,"rw"); EJrP{GH
this.nPos = nPos; ';Y0qitGB
oSavedFile.seek(nPos); Ko:<@h
} !Wgi[VB
!ap}+_IA7^
Ejmpg_kux
public synchronized int write(byte[] b,int nStart,int nLen) ^?}-x
{ 1N,</<"
int n = -1; qx|~H'UuBN
try{ \(C6|-:GY
oSavedFile.write(b,nStart,nLen); Z):q1:y
n = nLen; MR}=tO
} 4}`z^P<C
catch(IOException e) $i1$nc8
{ B 1jeIk,
e.printStackTrace (); -%,=%FBi~4
} yw\Q>~$n[=
{OIB/
=bgWUu\F
return n; kntYj}F(
} #Pt_<?JtV
qz95)
0~4Ww=#
} E6XDn`:
\xG_q>1_
@q]4]U)
/* 6+!$x?5|NP
**SiteInfoBean.java -!q^/ux
*/ TXdo,DPv7
package NetFox; {.eo?dQ
{^8?fJ/L
w{mw?0
public class SiteInfoBean { xu\s2x$
w$iQ,--
R#HVrzOO|T
private String sSiteURL; //Site's URL xIA]5@;a
private String sFilePath; //Saved File's Path OYSq)!:
private String sFileName; //Saved File's Name 'hR0JXy
private int nSplitter; //Count of Splited Downloading File GHY+q{'#V_
ZmI0|r}QbY
K @RGvP
public SiteInfoBean() DQ<4`wEM
{//nSplitter的缺省值为5 nr&bpA/
//default value of nSplitter is 5 ijP`fM8
this("","","",5); .exBU1Yk@
} uP G\1
>$,P )cB'
.dI".L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #lR-?Uh
{ $Q"D>Qf{G
sSiteURL= sURL; P?p]sLrP
sFilePath = sPath; |M`'
sFileName = sName; oR7[[H.4
this.nSplitter = nSpiltter; bmu]zJ
_o[fjd
pT{is.RM
} :{+~i.*
^hXm=r4ozR
KRz~3yH{c
public String getSSiteURL() wx^Det
{ hC[=e`j
return sSiteURL; kDol1v`
} E;}&2 a
9U8x&Z]P
,Qx]_gZ`
public void setSSiteURL(String value) `Fie'[F5,)
{ `JO>g=,4
sSiteURL = value; DQ(0:r
} 7Xx3s@
n]df)a
yts@cd`$
public String getSFilePath() R2v9gz;W
{ !( >U3N
return sFilePath; 2xf#@`U
} ?a#Gn2
_V4O#;%?
!KMl'kswe:
public void setSFilePath(String value) <rtKPlb//
{ /jNvHo^B
sFilePath = value; ! ui
} ^3[_4av
v^ "qr?3V
BBM[Fy37!}
public String getSFileName() ,`JYFh M
{ sC.b'1P
return sFileName; Q7rBc wm5
} (?m{G Q
2TUV9Z
& XmaGtt
public void setSFileName(String value) 1Gsh%0r3
{ V$?6%\M^*
sFileName = value; MgeC-XQM
} YnEyL2SuU
2][9Wp
8ymdg\I+L
public int getNSplitter() W'C>Fn}lO?
{ > Vm}u`x
return nSplitter; ]l,D,d81
} z@,pT"rb
|p:4s"NT
S2$66xr#
public void setNSplitter(int nCount) v\:AOY'
{ EpS/"adI-!
nSplitter = nCount; t]h_w7!U
} )]fsl_Yq
} s<!A<+Sh
V'kBF2}
]64Pk9z=
/* //&3{B
**Utility.java |/Vq{gxp+
*/ 2u]G]:ml
package NetFox; "S;4hO
!]F`qS>
bJ:5pBJ3
public class Utility { G<CD4:V
A?MM9Y}K
QNbZ)
public Utility() y4kn2Mw;
{ 9C7Npf?~M
ntIR#fB
e|tx`yA
} sVh)Ofn
WO>,=^zPJ
//线程睡眠 g:!U,<C^a
public static void sleep(int nSecond) "]eB2k_>
{ ]!TE
try{ k+"];
Thread.sleep(nSecond); :q/s%`ob
} KH2]:&6:Q
catch(Exception e) {iyJHY
{ #x.v)S
e.printStackTrace (); !$NK7-
} 8=D,`wog
} \`y:#N<c
?l~qb]._
//日志 2D:/.9= 8v
public static void log(String sMsg) |Ua);B~F
{ ,=e.QAF!"
System.err.println(sMsg); >~ *wPoW
} "`;-5dg
6?xF!VIL
5@RcAQb:
public static void log(int sMsg) f%PLR9Nh5@
{ 3^P;mQ$p1
System.err.println(sMsg); >K'dgJ245
} f@`|2wG
} R?1Z[N
jwjLxt
[.&JQ
/* Z'A 3\f
**TestMethod.java </kuJh\
*/ </'n={+q
package NetFox; ]-t>F
t<dFH}U`w
<cZ/_+H%C
public class TestMethod { z4 =OR@ h
)*_G/<N)|
u3Z]!l
public TestMethod() k5>UAea_
{ ///xx/weblogic60b2_win.exe tQG'f*4
try{ E!ZLVR.K
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); eV%{XR?y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); HY_>sD
SiteFileFetch fileFetch = new SiteFileFetch(bean); i\;ZEM{
fileFetch.start(); *A`ZcO=
} <r <{4\%}
catch(Exception e){e.printStackTrace ();} 5mV!mn:H:
Pm#/j;
i+5Qs-dHA
} `oe=K{aX
_1RvK? ;.{
]["%e9#aX
public static void main(String[] args) T*@o?U
{ 4<tbZP3/6)
new TestMethod(); dn}EM7:Z
} Ge({sy>X
} v6DjNyg<x
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