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)); x$cs_q]J
} GBGGV#_q'}
for(int i=0;i<nEndPos.length-1;i++) ?Xx,[Z&
{ (sq4
nEndPos = nStartPos[i+1]; U:M?Ji5CY
} 6NVf&;laQ
nEndPos[nEndPos.length-1] = nFileLength; #e((F,1z
} Mp:tcy,*
} ^^qB=N[';
rLw,?
Ont4-AP
//启动子线程 .>Gq/[c0|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; AhZ8B'Ee
for(int i=0;i<nStartPos.length;i++) l(-6pP5`
{ k+f!)7_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :[ F`tDL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jV;&*4if
nStartPos,nEndPos,i); zZ3,e L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eva-?+n\q
fileSplitterFetch.start(); s+gZnne
} )Fe-C
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F0t!k>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #DXC6f
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )cbe4
nEndPos = " + nFileLength); ]j(2FM)#
// fileSplitterFetch[nPos.length-1].start(); cor?#
x JQde4
}eXzs_
//等待子线程结束 7?:7}xb-
//int count = 0; GU8b_~Gk?
//是否结束while循环 ]rO`eN[~U
boolean breakWhile = false; WoHFt*e2
g>_lU vSE
.cdm@_Ls
while(!bStop) /%\E2+6
{ HF" v \
write_nPos(); a;|C51GH
Utility.sleep(500); *Em 9R
breakWhile = true; ?"]fGp6y
-o#HO_9
$?YRy_SI
for(int i=0;i<nStartPos.length;i++) T^x7w+
{ m646|G5
if(!fileSplitterFetch.bDownOver) J*Dj`@`4`g
{ f^@`[MJj1C
breakWhile = false; -x=abyD
break; 3@kiUbq7Eu
} *A':^vgk
} 6q RZ#MC
if(breakWhile) 7afD^H%
break; D^W6Cq5\
aL$m
h?jy'>T?b2
//count++; M:z)uLDw
//if(count>4) aT$q1!U`j2
// siteStop(); * xdS<
} lG;RfDI-
*G7$wW:?
uvz}qH@j/Q
System.err.println("文件下载结束！"); eN fo8xUG
} 7d*SZmD
catch(Exception e){e.printStackTrace ();} Ml1yk)3G
} -g(&5._,ZW
$=uyZTYF)}
!Sx}~XB<
//获得文件长度 H)(@A W+-
public long getFileSize() !:PF |dZ
{ FVNxjMm,
int nFileLength = -1; =G2D4>q
try{ S/Pffal
URL url = new URL(siteInfoBean.getSSiteURL()); HUiW#x%;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <GC<uB |p
httpConnection.setRequestProperty("User-Agent","NetFox"); OiH tobM
1H`T=:P?
6*u#^">,<
int responseCode=httpConnection.getResponseCode(); ^UHt1[
if(responseCode>=400) *9M 5'
{ Wly-z$\
processErrorCode(responseCode); mO;X>~K
return -2; //-2 represent access is error t<mT=(zt*
} %p6"Sg*
[,e[~J`C
Aq@_^mq1A
String sHeader; q[`)A?Ae
7Gd)=Q{uur
Is&z~Xy/
for(int i=1;;i++) I9O!CQCTt
{ {Tb(4or?=b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,TPNsz|Q
//Utility.log(in.readLine()); s1.YH?A;
sHeader=httpConnection.getHeaderFieldKey(i); t"k6wv;Tq
if(sHeader!=null) Fn.wd`'0
{ ig:,:KN
if(sHeader.equals("Content-Length")) A ^@:Ps
{ P -0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9r=@S
break; ikf!7-,
} W8+Daw1Nr
} ,=whwl "tA
else sJo]$/?F
break; ,Q!sns[T
} k0~mK7k
} Se/VOzzg
catch(IOException e){e.printStackTrace ();} U\'.rT[#
catch(Exception e){e.printStackTrace ();} NKf][!bi
6KC.l}Y*
a<9gD,]P
Utility.log(nFileLength); |Z'NMJU
HTiqErD2_
|!:ImX@
return nFileLength; tn!z^W
} n:d]Z2b
HEHTj,T
f(~xdR))eh
//保存下载信息（文件指针位置） u&Ts'j
private void write_nPos() |:Gz9u+
{ .|`JS?L[
try{ d1VNTB
output = new DataOutputStream(new FileOutputStream(tmpFile)); CnyCEIO-
output.writeInt(nStartPos.length); qDZ?iTHQq
for(int i=0;i<nStartPos.length;i++) Ht|No
{ YSERQo
// output.writeLong(nPos); #12
output.writeLong(fileSplitterFetch.nStartPos); nTxeV%
output.writeLong(fileSplitterFetch.nEndPos); *X- 6]C
} 0Ou;MU*v
output.close(); H1X38
} jq#gFt*
catch(IOException e){e.printStackTrace ();} PhL}V|W>
catch(Exception e){e.printStackTrace ();} Q`k=VSUk
} ep`WYR|B
tj/X7|
(PAkKY}
//读取保存的下载信息（文件指针位置） 4#Wczk-b
private void read_nPos() `(s&H8x#
{ P @N7g`u3}
try{ >MD['=J[d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6U[`CGL66
int nCount = input.readInt(); &1)4B
nStartPos = new long[nCount]; m`luMt9
nEndPos = new long[nCount]; 8JxJ>I-9p
for(int i=0;i<nStartPos.length;i++) @b[{.mU
{ x~p8Mcv
nStartPos = input.readLong(); pJ35M
nEndPos = input.readLong(); P(pw$ q$S
} h{xC0NC)
input.close(); vW,dJ[N6jm
} wz^Q,Od
catch(IOException e){e.printStackTrace ();} NFq&a i
catch(Exception e){e.printStackTrace ();} *6D0>F
} _aa3;kT_
J60XUxf
5u +U^D
private void processErrorCode(int nErrorCode) :{@&5KQ8)
{ s%F}4W2s
System.err.println("Error Code : " + nErrorCode); .%)FK#s-
} ;Q"xXT`;:
2@K D '^(
_h|rH
//停止文件下载 `kb]tf
public void siteStop() v5STe`
{ 9}p>='
bStop = true; q SR\=:$
for(int i=0;i<nStartPos.length;i++) -4ityS @
fileSplitterFetch.splitterStop(); LVNq@,s
j\l9|vpp
H]&a}WQ_
} &4 Py
} 'p<lfT
//负责部分文件的抓取 YjaEKM8*
**FileSplitterFetch.java 1@Abs
*/ +vOlA#t%Z
package NetFox; T"7Ue
7u[U%yd
K;,zE6WD$$
import java.io.*; ;UuCSfs{
import java.net.*; O[ tD7!1
htC~BK3(
{A2EGUmF2
public class FileSplitterFetch extends Thread { Bk,:a,
Co[fq3iX#
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String sURL; //File URL ]WlE9z7:8
long nStartPos; //File Snippet Start Position /d;C)%$
long nEndPos; //File Snippet End Position Gx Z'"x
int nThreadID; //Thread's ID J2A+x\{<
boolean bDownOver = false; //Downing is over k#mQLv
boolean bStop = false; //Stop identical 1>hY!nG h
FileAccessI fileAccessI = null; //File Access interface X(sHFVU+
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g/Q"%GN,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5(BB`)
{ _,*ld#'s
this.sURL = sURL; W/03L, 1
this.nStartPos = nStart; k?r-%oJ7
this.nEndPos = nEnd; 9G njJ
nThreadID = id; hP1}Do
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _$s ;QI]x
} pxm{?eBz
-|E|-'
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public void run() 5G5P#<Vv
{ zTA+s 2
while(nStartPos < nEndPos && !bStop) 0*!CJ;%N
{ ]2O52r
@JJ,$?
CjtBQ5
try{ <1")JDW
URL url = new URL(sURL); SN w3xO!;&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BET3tiHV
httpConnection.setRequestProperty("User-Agent","NetFox"); B~S"1EE[
String sProperty = "bytes="+nStartPos+"-"; _X ?W)]:
httpConnection.setRequestProperty("RANGE",sProperty); LxD >eA
Utility.log(sProperty); wHneVqI/U
`qP <S
FR%9Qb7
InputStream input = httpConnection.getInputStream(); zadn`B#2
//logResponseHead(httpConnection); XLwmXi
IE/F =Wr
z1wJ-l
byte[] b = new byte[1024]; w-f[h
int nRead; P#e1?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M#<U=Ha
{ !~X[qT
nStartPos += fileAccessI.write(b,0,nRead); s?qRy 2
//if(nThreadID == 1) >`\f,yql6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ahezDDR-.i
} e,j2#wjor
5R^e
pPI'0x
Utility.log("Thread " + nThreadID + " is over!"); ~W?F.
bDownOver = true; UO3QwZ4j;
//nPos = fileAccessI.write (b,0,nRead); +Fn^@/?yC
} luA k$Es
catch(Exception e){e.printStackTrace ();} [!^Q_O
} 8sMDe'
} kjCXP
&)(>e}es
#jY\l&E
//打印回应的头信息 9 Vn
public void logResponseHead(HttpURLConnection con) ZUDdLJ
{ Vz=ByyC
for(int i=1;;i++) 82w;}(!
{ l,z# :k
String header=con.getHeaderFieldKey(i); _hM #*?}v
if(header!=null) wUUDq?!k\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); M5$YFGGR
Utility.log(header+" : "+con.getHeaderField(header)); %}< e;t-O
else VD=}GY33=
break; z"cF\F
} &/%A 9R,
} XwI~ 0
~ ^)D#Lo
xZmO^F5KHj
public void splitterStop() x3./
{ Cxn<#Kf\-<
bStop = true; *t_"]v-w
} "EA6RFRD
;3\oU$'
E;$;g#ksf
} BQX6Q<
aT9+] Ig
qN5 ru2
/* gmCW__oR
**FileAccess.java <Mdyz!
*//文件访问(定位，写) j@yK#==k
package NetFox; /O,>s
import java.io.*; nC-=CMWWr
G~$.Af!9W
bfjC:"!H
public class FileAccessI implements Serializable{ 4CUoXs'
2(SU# /,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <>gX'te
RandomAccessFile oSavedFile; }}R?pU_
long nPos; )@vhqVv?
&sFEe<
=[N=mC
public FileAccessI() throws IOException x,CTB
{ 79DzrLu
this("",0); S5Hb9m&&
} kTC'`xv
:K:oH}4oh
|E%i t?3M
public FileAccessI(String sName,long nPos) throws IOException ~0;l\^
{ Yf=an`"
oSavedFile = new RandomAccessFile(sName,"rw"); 4trP*u,4
this.nPos = nPos; Ry$zF~[
oSavedFile.seek(nPos); we4k VAn
} !ucHLo3:
]xx}\k
F&tU^(7<
public synchronized int write(byte[] b,int nStart,int nLen) Dd:TFZo
{ h/)kd3$*'
int n = -1; *3uBS2Ld
try{ >i6sJ)2?>
oSavedFile.write(b,nStart,nLen); l**gM
n = nLen; k-:wM`C
} ^{Vt
catch(IOException e) #8Bs15aV
{ u-8b,$@Z>'
e.printStackTrace (); S.<aCN<@
} a#huK~$~
>yZe1CP
J?oI%r7^
return n; w5C$39e\G
} m;_gNh8Ee
\ oY/hT_
6KvoHo
} wjq;9%eXk
Fjs:rZ#{
KF4D)NM|
/* Z<yLu'48)A
**SiteInfoBean.java vz$_Fgsc.
*/ {^5LolCCH
package NetFox; Wz8MV -D
|)Q#U$ m
kFRl+,bi~
public class SiteInfoBean { gwA+%]
N$!aP/b
}Wk^7[Y
private String sSiteURL; //Site's URL qG6?k}\\
private String sFilePath; //Saved File's Path "jUM}@q5
private String sFileName; //Saved File's Name |;(95
private int nSplitter; //Count of Splited Downloading File P&>!B,f
6>yfm4o
~nVO%IxM4J
public SiteInfoBean() azs lNL
{//nSplitter的缺省值为5 gNWTzz<[f>
//default value of nSplitter is 5 Lhts4D/V7
this("","","",5); rIh"MQvi[
} g3Xab
l.@v@T(/
#`HY"-7m_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +HXR ))X
{ 8opd0'SNaB
sSiteURL= sURL; rWP -Rm
sFilePath = sPath; o]@Mg5(8Q
sFileName = sName; n@JZ2K4
this.nSplitter = nSpiltter; '^{:HR#i
nF)b4`Nd
f@j)t%mh
} _.{I1*6Y2
qk{+Y
@W1F4HYds
public String getSSiteURL() 2Y7u M;8
{ n9%&HDl4
return sSiteURL; b2tUJ2p
} ppP0W`p
R<L<kChg
x 8/I"!gI
public void setSSiteURL(String value) t:O"t G
{ KLBX2H2^0
sSiteURL = value; ( kKQs")
} Gp9:#L!
W]CsKN,K
~Z>!SMXp<
public String getSFilePath() 6Mj(B*c
{ Z1y=L$t8
return sFilePath; Mb^E
} ,J4rKGG
W\pO`FL
WAUgbImc{
public void setSFilePath(String value) Xl %ax!/
{ ?'IY0^
sFilePath = value; Tb[1\
} z[sP/{~z
k d9<&.y{
p.|M:C\xL
public String getSFileName() a;h.I}*]
{ V#,jUH|
return sFileName; wj{[g^y%
} >+FaPym
sqEOXO
nJhaI
public void setSFileName(String value) _+6aD|7x
{ ~QngCg-5q
sFileName = value; Fl}{"eCF8
} <}Hs@`jS
n)uck5
M-V{(
public int getNSplitter() KK';ho,W
{ O63:t$Yx#
return nSplitter; UbEK2&q/8
} .Y5o&at6s
asZ(Hz%
EXEB A&*
public void setNSplitter(int nCount) 4de:hE
{ GWa:C\YK
nSplitter = nCount; ?0x=ascP
} -d4|EtN
} H7{I[>:
928uGo5
l{mC|8X
/* EdTR]}8
**Utility.java mlO\wn-F
*/ ?`/DFI'_G
package NetFox; WyU\,"
=mYwO=:D
Y=ksrs>w
public class Utility { =$-+~
a797'{j#PI
2_GbK-
public Utility() WNSY@q
{ gVI{eoJ
Q*ixg$>
*TgD{>s
} [ 0z-X7=e
)?;+<,
//线程睡眠 [?55vYt
public static void sleep(int nSecond) )m$MC25
{ ;-^8lWt
try{ ~7>D>!!
Thread.sleep(nSecond); O_ d[{e=5`
} g`(3r
catch(Exception e) c<ORmg6
{ dwqR,|
e.printStackTrace (); \IP 9EFA
} uH |:gF^
} P?hB`5X
+-:o+S`q~
//日志 ?k^~qlye
public static void log(String sMsg) b8LA|#]i
{ 4x-K0
System.err.println(sMsg); yVe<+Z\7
} dK41NLGQ
bJcO,M:2
"i,ZG$S#E
public static void log(int sMsg) ZkryoIQ%=
{ :[&QoEZW
System.err.println(sMsg); l?B=5*0
} a"D'QqtH
} 8osP$"/o
)%09j0y>l"
'Pe;Tp>`
/* #A&49a3^1
**TestMethod.java ldnKV&N
*/ :3[;9xCHj
package NetFox; }=d}q *
k\X yR4r
& zv!cf
public class TestMethod { #$;}-*
^/I.? :+
gh `]OxA
public TestMethod() \ #N))gAQ
{ ///xx/weblogic60b2_win.exe ^p~QHS/
try{ i`5Skr:M
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &Qmb?{S0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $IqubC>O
SiteFileFetch fileFetch = new SiteFileFetch(bean); :{9HsF"h0
fileFetch.start(); z@?WhD
} j&[u$P*K
catch(Exception e){e.printStackTrace ();} ~KczP1p
pM9M8d
]app9
} #nq_R
%-[*G;c'w
$Lz!04
public static void main(String[] args) (9{qT>eJg=
{ +g;{c+Kw:
new TestMethod(); LkWY6 ?$U
} z.^_;Vql_
} Fj46~#ZZ
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