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)); N8|=K_;&
} "f\2/4EIl
for(int i=0;i<nEndPos.length-1;i++) zq-"jpZG
{ {^gbS
nEndPos = nStartPos[i+1]; AEaT
} &WAO.*:y
nEndPos[nEndPos.length-1] = nFileLength; n~N>c*p
} e_s9E{(
} *f|9A/*B3
T">-%-t
2T/C!^iJ)
//启动子线程 +N1oOcPC>C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?F'gh4
for(int i=0;i<nStartPos.length;i++) y]QG;
{ hWpn~q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CL%?K<um
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MVHj?
nStartPos,nEndPos,i); &RP!9{F<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <y1V2Np
fileSplitterFetch.start(); LcCb[r
} +cv7]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;Vc@]6Ck
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6J0HaL
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u38FY@U$
nEndPos = " + nFileLength); JmdXh/X
// fileSplitterFetch[nPos.length-1].start(); rhY>aj
.b>1u3
R)?b\VK2$
//等待子线程结束 <(W0N|1v
//int count = 0; yyZH1A
//是否结束while循环 ,!_
boolean breakWhile = false; 2h0I1a,7
49n.Gc
V3baEy>=z
while(!bStop) (.\GI D+i
{ 6$[7t?u
write_nPos(); Bmuf[-}QW
Utility.sleep(500); 9],;i7c
breakWhile = true; 3;=nQ{0b
:gv`)
0L10GJ"(
for(int i=0;i<nStartPos.length;i++) [o8a(oC
{ 1\1a;Q3W%,
if(!fileSplitterFetch.bDownOver) X1G[&
{ fU^B 3S6X
breakWhile = false; ^c{}G<U^
break; O-B~~$g
} O @fX +W?U
} ,GEMc a,`
if(breakWhile) j-|YE?AA
break; GXB4&Q!C
RL/~E xYC
BX$t |t;!m
//count++; Y W_E,A>h
//if(count>4) <$Q\vCR
// siteStop(); 4S|! iOY
} X&DuX %x0
|8}f
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System.err.println("文件下载结束！"); *>%34m93
} ):?ype>
catch(Exception e){e.printStackTrace ();} TN3, \qgV
} T.="a2iS2
8}h ^Frh
?^P#P0
//获得文件长度 YfUdpa0
public long getFileSize() m! &bK5+*
{ Kv"e\ E
int nFileLength = -1; awuUaE
try{ Zy@35;r
URL url = new URL(siteInfoBean.getSSiteURL()); %Q"zU9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ga~N7
httpConnection.setRequestProperty("User-Agent","NetFox"); _i~n!v
]YkF^Pf!v
[9UKVnX.V
int responseCode=httpConnection.getResponseCode(); g6EdCG.V
if(responseCode>=400) xG0IA 7
{ w=\Lw+X
processErrorCode(responseCode); YXXUYi~!f
return -2; //-2 represent access is error Z:aDKAboU
} 9x.vz
OqUEj 0X
wqBGJ
String sHeader; LA$uD?YA
1Lwi?~!LI
0K7]<\)
for(int i=1;;i++) pVn6>\xa
{ lqAU5K{wQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); USu/Y29
//Utility.log(in.readLine()); (FZL>
sHeader=httpConnection.getHeaderFieldKey(i); ==(9P`\
if(sHeader!=null) 7|PpAvMF
{ nS[0g^}
if(sHeader.equals("Content-Length")) b_ Sh#d&
{ 0TU~Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uoFH{.)
break; wE3^6
} ba|x?kz
} )/2* <jr
else jo=XxA
break; y=YD4m2W
} &Th/Qv}[
} td4*+)'FY
catch(IOException e){e.printStackTrace ();} 94I8~Jj4
catch(Exception e){e.printStackTrace ();} @]tFRV
F0:Fv;
* b>W
Utility.log(nFileLength); wRf_IBhCd
1JgnuBX"
mB;W9[
return nFileLength; <oV _EZ
} i:OD)l
G,>tC`!
/a17B
//保存下载信息（文件指针位置） z_!P0`
private void write_nPos() 8<3J!X+
{ _Pa(5-S'KR
try{ D9e"E1f+"
output = new DataOutputStream(new FileOutputStream(tmpFile)); e%x$Cb:znn
output.writeInt(nStartPos.length); 0sVCTJ@
for(int i=0;i<nStartPos.length;i++) zm2&\8J
{ #QZg{
// output.writeLong(nPos); Eag->mw/~
output.writeLong(fileSplitterFetch.nStartPos); KJ,{w?p~ )
output.writeLong(fileSplitterFetch.nEndPos); <;#d*&]
} $y\'j5nk3
output.close(); t-dN:1
} JXBW0|8b
catch(IOException e){e.printStackTrace ();} /7|u2!#Ui
catch(Exception e){e.printStackTrace ();} 7~cN
} 9cFFQM|o
|U1X~\""
&GwBxJ
//读取保存的下载信息（文件指针位置） R`G%eG)+
private void read_nPos() N<Rb<p%
{ /4RKA!W
try{ n5 @H
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); s\#kqw\x
int nCount = input.readInt(); 2uS&A \
nStartPos = new long[nCount]; ujB:G0'r
nEndPos = new long[nCount]; -`]B4Nt6
for(int i=0;i<nStartPos.length;i++) ]jG%<j9A
{ W5$jIQ}Bw
nStartPos = input.readLong(); Z4}Yw{=f
nEndPos = input.readLong(); Y[$[0
} FOB9CsMe
input.close(); 1>bkVA
} W>dS@;E
catch(IOException e){e.printStackTrace ();} 4a>z]&s
catch(Exception e){e.printStackTrace ();} !OPK?7
} _.J{U0N
^w^cYM,
W6&".2
private void processErrorCode(int nErrorCode) [:a;|t
{ @`k!7? Sq
System.err.println("Error Code : " + nErrorCode); Ee9u7TFT
} s?=f,I
NeCTEe|V
#g4X`AHB
//停止文件下载 xex/L%!Rj
public void siteStop() 6;dB
{ dSsMa3X[n
bStop = true; zi2hi9A
for(int i=0;i<nStartPos.length;i++) #$K\:V+ 4
fileSplitterFetch.splitterStop(); P`[6IS#\S
#1z}~1-
S#!PDg
} j!&g:{ e
} +;`Cm.Iu
//负责部分文件的抓取 /QHvwaW[
**FileSplitterFetch.java o&rejj#
*/ }pPxN@X
package NetFox; mY(~94{d
PPDm*,T.
.pu]21m=
import java.io.*; `iv,aQ '
import java.net.*; |w6:mtaS
+H/^RvUjF
!s\-i6S>
public class FileSplitterFetch extends Thread { @`$8rck`
D?qA aq&4
dy,,x
String sURL; //File URL T*J]e|aF
long nStartPos; //File Snippet Start Position $>OWGueq64
long nEndPos; //File Snippet End Position Wxb/|?,
int nThreadID; //Thread's ID hX$k8 o0
boolean bDownOver = false; //Downing is over GpN tvo~
boolean bStop = false; //Stop identical }UHuFff,
FileAccessI fileAccessI = null; //File Access interface 76} N/C
0mH>fs 4
oO$a4|&,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #`);UAf
{ 7O;v5k~iQ
this.sURL = sURL; nW{). P
this.nStartPos = nStart; h<6@&yzp
this.nEndPos = nEnd; ?t'O\n)M
nThreadID = id; PS`v3|d}}}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (Pin9^`ALc
} "%<Oadz ap
6~&4>2b0f
)]n:y M
public void run() h/V0}|b
{ ~${.sD\
while(nStartPos < nEndPos && !bStop) d#vq+wR
{ P`Anf_
a)Qx43mOS
o9<jj>R;
try{ r?\hZ*|M
URL url = new URL(sURL); @/`b:sv&*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <{9E.6G`n
httpConnection.setRequestProperty("User-Agent","NetFox"); t{Q9Kv
String sProperty = "bytes="+nStartPos+"-"; #";(&|7
httpConnection.setRequestProperty("RANGE",sProperty); FX+Ra@I!
Utility.log(sProperty); C \H%4p1r
fE|([` !
fHb0pp\[.
InputStream input = httpConnection.getInputStream(); Y=x]'3}^
//logResponseHead(httpConnection); O>Xyl4U
$a(wM1S4
`+\+
byte[] b = new byte[1024]; +<"sC+2
int nRead; 9-Qub+0o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IpB0~`7YI
{ |mc!v*O
nStartPos += fileAccessI.write(b,0,nRead); x>!#8?-h
//if(nThreadID == 1) Av_1cvR:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o\g",O4-
} p(v+j_ak
i0L)hkV
;I:jd")
Utility.log("Thread " + nThreadID + " is over!"); ljlQ9wb[s
bDownOver = true; nr!kx)j
//nPos = fileAccessI.write (b,0,nRead); 55zimv&DV
} 4Xe3PdE
catch(Exception e){e.printStackTrace ();} 'X<R)E
} J5mMx)t@
} Nf}G "!
]gQgNn?
qI) Yzc/
//打印回应的头信息 T,!?+#
public void logResponseHead(HttpURLConnection con) JyjS#BWi
{ [q?{e1
for(int i=1;;i++) -SlLX\>p
{ 0V}%'Ec<e
String header=con.getHeaderFieldKey(i); L/F!Y%=;[
if(header!=null) ql2>C.k3L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2Af1-z^^K
Utility.log(header+" : "+con.getHeaderField(header)); -$QzbRF5R
else wg<DV!GZ
break; H`9E_[
} W-<C%9O!
} mKvk6OC
-Z-|49I/mN
a^@6hC>sr
public void splitterStop() MkRRBvk
{ f}Mc2PQ-
bStop = true; {qp XzxV
} 8)\ ?6C
;xN4L
dK#:io[Nz
} HKP<=<8/O
TXv3@/>ZlG
E"b+Q
/* 0%<Fc9#
**FileAccess.java {uM*.]
*//文件访问(定位，写) jri=UGf
package NetFox; ^Cst4=:W
import java.io.*; \uc]+nV!o
V) a<)
x<>#G~-
public class FileAccessI implements Serializable{ ]L"jt8E
?R(fxx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yS0!#AG
RandomAccessFile oSavedFile; X"z^4?Aj+
long nPos; K pDKIi
~5N0=)
5*/~) wN\U
public FileAccessI() throws IOException -v/1R1$e1
{ Ovxs+mQ
this("",0); [1F.
} pi*cO
Eh^c4x
`+CRUdr
public FileAccessI(String sName,long nPos) throws IOException jL8.*pfv
{ 2`9e20
oSavedFile = new RandomAccessFile(sName,"rw"); ~Y7>P$G)
this.nPos = nPos; ^":UkPFCx:
oSavedFile.seek(nPos); D|9xD
} )[C]1N=tK
b(Zh$86
fa//~$#"{L
public synchronized int write(byte[] b,int nStart,int nLen) 6ey{+8
{ b}HLuX
int n = -1; )\s{\u \
try{ C< 3`]l
oSavedFile.write(b,nStart,nLen); g`i?]6c}jt
n = nLen; ;.Zgt8/.
} "oz : & #+
catch(IOException e) T`mG+"O
{ +DmfqKKbd
e.printStackTrace (); 6!sC
} 5Tag-+
0ft81RK
]$oo1ssZ1
return n; Ngi]I#Vz
} oJ734v[X
Xia4I* *
O`j1~o<{
} Lp.dF)C\
%CV@FdB
-N $4\yp
/* :[xFp}w{
**SiteInfoBean.java <'N"GLJ
*/ }$iKz*nx|
package NetFox; ?l/VCEZP
lHerEv<ja
O?L6Ues
public class SiteInfoBean { He vZ}.
a> qB k})
[U'I3x,
private String sSiteURL; //Site's URL c|m*< i
private String sFilePath; //Saved File's Path NXo$rf:
private String sFileName; //Saved File's Name 4zKmoYt
private int nSplitter; //Count of Splited Downloading File v+Mi"ZAd
hGh91c;4
l7 Pn5c
public SiteInfoBean() 2T 3tKX
{//nSplitter的缺省值为5 pse$S=
//default value of nSplitter is 5 0Lb:N]5m8
this("","","",5); opsjei@
} xl2;DFiYt
%])U(
w_qX~d/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V1di#i:
{ xKl\:}Ytp
sSiteURL= sURL; AK$&'t+$}7
sFilePath = sPath; *ThP->&:(
sFileName = sName; 41G}d+
this.nSplitter = nSpiltter; @=rYOQj|
NW_i<#
0RFBun{
} ;$,b w5
n=Ze p{^
JOwm|%>3a
public String getSSiteURL() 42$ pvw<
{ 8k +^jj
return sSiteURL; |ht:_l 8
} 7md,!|m
gZq_BY_U
h'lqj0
public void setSSiteURL(String value) |2ImitN0
{ ":@\kw
sSiteURL = value; ~'1gX`o:
} &A}hx\_T
B']-4X{SGa
fk&>2[^&
public String getSFilePath() rj}O2~W~4
{ >PuQ{T I
return sFilePath; hZ_@U?^
} VOJA}$
cYmgJBG
Th_PmkvC
public void setSFilePath(String value) B@w/wH
{ /_SQKpic
sFilePath = value; ibH!bS{
} hXnfZx%
A(eB\qG
PH.g+u=v
public String getSFileName() %>'Zy6C<j
{ _=Z?5{7S>
return sFileName; S5o,\wT
} ?}RPnf
qP{Fwn
3c%_RI.
public void setSFileName(String value) gFpub_
{ f+!k:}K
sFileName = value; T<oDLJA\
} R_W6}
=U7P\sw2
1-V"uLy@gC
public int getNSplitter() P{,A%t
{ UpaF>,kM
return nSplitter; ee/3=/H|;
} v]Fw~Y7l!
(/7b8)g
'Zs3b4n8
public void setNSplitter(int nCount) iC{(vL0P+
{ U ,NGV0
nSplitter = nCount; OUq%d8W
} GQ(*k)'a
} {p.^E5&
.Hnhd/ c
ayI<-s-
/* oN2#Jh%dH
**Utility.java ,eGguNA9
*/ GKc?
package NetFox; 7KesfH?
> ^=n|%
~R&rQJJeJ
public class Utility { qj9[mBkP"
U&i#cF
Z`_x|cU?J
public Utility() Lk)I;;
{ C$p012D1
L;lu)|b"
i?ZVVE=r
} !2Gua1z!CJ
ZC]|s[
//线程睡眠 NH;e|8
public static void sleep(int nSecond) f&j\gYWq
{ A9lw^.
try{ eC"k-a8j+
Thread.sleep(nSecond); up{0ehr
} 4E2#krE%
catch(Exception e) Sg$\H
{ ?q7MbQw
e.printStackTrace (); DKJ_g.]X
} b@c(Nv
} AyWdJ<OU
E[WU
//日志 #.rkvoB0N
public static void log(String sMsg) wz1nV}
{ -oUGmV_
System.err.println(sMsg); N5{v;~Cm}V
} 2Z(t/Zp>
X-tw)
)ut$644R
public static void log(int sMsg) -RJ~Sky[
{ =igTY1|af
System.err.println(sMsg); ^vxx]Hji
} ,,H;2xYf
} F!3p )?
ep~+]7\
ber&!9
/* 0$ON`Vsu|
**TestMethod.java &@,lF{KTL
*/ ZJF"Yo
package NetFox; %%F,G
Ell14Iki
'z^'+}iyv
public class TestMethod { je@&|9h
(a0(ZOKH
Mk~U/oq
public TestMethod() e]nP7TIU
{ ///xx/weblogic60b2_win.exe oKYa?
try{ 8o[gzW:Q)U
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >;XtJJS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); X&HYWH'@,
SiteFileFetch fileFetch = new SiteFileFetch(bean); -. o,bg
fileFetch.start(); Rz&`L8Bz
} Zr1"'+-
catch(Exception e){e.printStackTrace ();} (u^8=#
g4=C]\1
IqV"4
} Ux1j+}y
-8l(eDm"m
Gk+R,:
public static void main(String[] args) |||m5(`S
{ VXiU5n^
new TestMethod(); )sW!s3>S>
} pfu"vo(t_
} |{(JUXo6K
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