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)); /1r{z1pv\
} zZV9`cqZ{
for(int i=0;i<nEndPos.length-1;i++) ]K<7A!+@@p
{ H)K.2Q
nEndPos = nStartPos[i+1]; oB+@05m8
} 3GZrVhU?m
nEndPos[nEndPos.length-1] = nFileLength; 8vUq8[[
} "p&4Sn3T2?
} Dj w#{WR
W;8}`k
s_6Iz^]I
//启动子线程 z{qn|#}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Bc}e ??F
for(int i=0;i<nStartPos.length;i++) Sbj{)
{ FOqD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Qe=eer~jI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :kucDQE({?
nStartPos,nEndPos,i); Qq\hD@Z|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U"K%ip:Wd
fileSplitterFetch.start(); +b{tk=Q:
} &9xcP.3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [8[`V)b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ),0Ea~LB4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", p0HcuB)Y
nEndPos = " + nFileLength); #twl
// fileSplitterFetch[nPos.length-1].start(); |tO.@+[uqP
7gt%[r M
$oZV 54
//等待子线程结束 D+*_iM6[-
//int count = 0; K Z0%J5
//是否结束while循环 r7v1q
boolean breakWhile = false; Ft8ii|-
['l}*
dj3E20Ws
while(!bStop) a<Ps6'
{ B|rf[EI>
write_nPos(); F/D/1w^ iR
Utility.sleep(500); 9>d~g!u=
breakWhile = true; xGX U7w:X
u2l`% F`x
cA`X(Am6]g
for(int i=0;i<nStartPos.length;i++) aMyf|l.
{ ~-NlTx
if(!fileSplitterFetch.bDownOver) d C6t+
{ o[nr)
breakWhile = false; qox@_
break; |exjrsmM*
} bd`}2vr
} "R-Pe\W
if(breakWhile) 2}.EFQp+
break; ~Yl%{1
o]0\Km
M\=/i\-
//count++; /^Zgv-n
//if(count>4) 0+_:^z
// siteStop(); yzz(<s:o/
} )H<F([Jri
y;tX`5(fe
d~O)mJ J
System.err.println("文件下载结束！"); m[&pR2T
} y-vBC3
catch(Exception e){e.printStackTrace ();} ,in"8aT}~
} CSIsi]H
!,;/JxfgVh
.4,l0Nn`W
//获得文件长度 3d>xg%?
public long getFileSize() S{)'1J_0
{ q6V\n:hKV
int nFileLength = -1; q]z%<`.9*
try{ 9'h4QF+Y
URL url = new URL(siteInfoBean.getSSiteURL()); *AI?md
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s#V:! 7
httpConnection.setRequestProperty("User-Agent","NetFox"); ~H`(zzk
P!lTK
hgF4PdO1e
int responseCode=httpConnection.getResponseCode(); FQikFy(YY
if(responseCode>=400) )cxML<j'
{ BxGz4
processErrorCode(responseCode); c`!8!R
return -2; //-2 represent access is error [214b=
} wTu=v
i^6g1"h
<@H=XEn
String sHeader; X:gE mcXc
AO^c=^
nV?e(}D
for(int i=1;;i++) j*@EJ"Gm>
{ O.wk*m!9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -'::$ {
//Utility.log(in.readLine()); )Xd2qbi
sHeader=httpConnection.getHeaderFieldKey(i); F5/,H:K\
if(sHeader!=null) kI#yW!
{ y ;T=u(}
if(sHeader.equals("Content-Length")) di#:KW
{ 2W=am_\0e.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o`ijdg!5qG
break; ? Eh)JJt
} /N\[ C"8
} uHpSE?y/
else Ke,$3Yx
break; ='GY:.N
} @`#"6y?
} >,QW74o
catch(IOException e){e.printStackTrace ();} _;`g*Kx
catch(Exception e){e.printStackTrace ();} ]iVoF N}^
$61*Xf+*
# >L^W7^
Utility.log(nFileLength); *heX[D &>)
wUbLw
>EIV`|b$h
return nFileLength; nV+]jQ~o
} _.$g?E/(
@;H1s4OZ
P :D6w){
//保存下载信息（文件指针位置） 5nJmabw3
private void write_nPos() XKT2u!Lx
{ L#NW<T
try{ X|X~|&j
output = new DataOutputStream(new FileOutputStream(tmpFile)); lhhp6-r
output.writeInt(nStartPos.length); $4*k=+wS
for(int i=0;i<nStartPos.length;i++) z9[BQ(9t
{ 4?9cyv4H
// output.writeLong(nPos); 4+_r0
output.writeLong(fileSplitterFetch.nStartPos); }@S''AA\
output.writeLong(fileSplitterFetch.nEndPos); :6X?EbXhK
} L BP|
output.close(); 0'.7dzz
} YkbZ 2J*-
catch(IOException e){e.printStackTrace ();} \%011I4
catch(Exception e){e.printStackTrace ();} S)[$F}
} tcU4$%H/
Af_yb`W?
A/{0J\pA
//读取保存的下载信息（文件指针位置） dk4|*l-
private void read_nPos() h2]gA_T`
{ dJwE/s
try{ ![#>{Q4i
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Rt10:9Kz$
int nCount = input.readInt(); 3"J85V%h]n
nStartPos = new long[nCount]; l\{{iAC]I
nEndPos = new long[nCount]; u4p){|x7s
for(int i=0;i<nStartPos.length;i++) v22ZwP
{ p[lciWEW
nStartPos = input.readLong(); V57tn6>b
nEndPos = input.readLong(); QUU'/e2^c
} &lYe
input.close(); *ioVLt,:R
} j9Y'HU5"
catch(IOException e){e.printStackTrace ();} &DgJu.
catch(Exception e){e.printStackTrace ();} SH${\BKup
} SvD^'( x
t)/:VImY
^-i<TJ
private void processErrorCode(int nErrorCode) ;+h-o
{ ' ;PHuMY#X
System.err.println("Error Code : " + nErrorCode); 3m9ab"
} Ue22,Pp6
8f0Ytfhw
4?)-;Hx_X
//停止文件下载 t&99ZdE
public void siteStop() M8wEy_XB1
{ gr y]!4Hy
bStop = true; ;3H#8x-
for(int i=0;i<nStartPos.length;i++) p+>vX X
fileSplitterFetch.splitterStop(); zgh~P^Z
K9(Su`zr
0ynvn9@t
} ,S7g=(27(
} KDzTe9
//负责部分文件的抓取 YZH&KGY
**FileSplitterFetch.java D-IXO@x
*/ BE]PM nI
package NetFox; 9s}y*Vp
BCtm05
8S_v} NUm
import java.io.*; L&2 Zn{#`
import java.net.*; CnA0^JX
AT%@T|
-I\Y m_)
public class FileSplitterFetch extends Thread { (ug^2WG Yq
Htu}M8/4
oTqv$IzqP
String sURL; //File URL ADQ#qA,/
long nStartPos; //File Snippet Start Position Q7-d]xJ^
long nEndPos; //File Snippet End Position x.OCE`
int nThreadID; //Thread's ID t$W~X~//
boolean bDownOver = false; //Downing is over xEfz AJ5&
boolean bStop = false; //Stop identical bez_|fY{T
FileAccessI fileAccessI = null; //File Access interface $WV N4fg
]7ZY|fP2
c<gvUVHIxR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _PR><L_
{ OAhCW*B
this.sURL = sURL; bq<DW/
this.nStartPos = nStart; >x$.mXX{
this.nEndPos = nEnd; f*}H4H EO
nThreadID = id; jZ8#86/#{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1hQeuG
} tb@&!a$`?
i!jR>+
lrXi*u]
public void run() UFoxv)
{ tL!R^Tf
while(nStartPos < nEndPos && !bStop) C;&44cU/]
{ /v,H%8S
s28rj6q
'[nH]N
try{ 3:;2Av2(X.
URL url = new URL(sURL); j\Z/R1RcW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,,-g*[/3
httpConnection.setRequestProperty("User-Agent","NetFox"); X-&U-S;
String sProperty = "bytes="+nStartPos+"-"; *mgK^9<
httpConnection.setRequestProperty("RANGE",sProperty); |rDv!m
Utility.log(sProperty); 0Q1sJDa.
</OZ,3J=
pg%'_+$~m
InputStream input = httpConnection.getInputStream(); 0rtP :Nj$
//logResponseHead(httpConnection); ZKv^q%92
)+nY-DB(
x*" 0dYH
byte[] b = new byte[1024]; LS=HX~5C
int nRead; 'L"dM9#>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )fo9Qwe
{ &u_s*
nStartPos += fileAccessI.write(b,0,nRead); UaQR0,#0y
//if(nThreadID == 1) :i4>&4j
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %0z&k!P
} SbLx`]rI
#$GDKK
O#e'.n!rI
Utility.log("Thread " + nThreadID + " is over!"); BWbM$@'x
bDownOver = true; wlM"Zt
//nPos = fileAccessI.write (b,0,nRead); 'NJCU.lKm
} 5+gSpg]i
catch(Exception e){e.printStackTrace ();} ;c-J)Ky
} Q@in?};
} 1Ue;hu'q:
V*m@Rs!)2
G@O~*k1v
//打印回应的头信息 <L1;aNN
public void logResponseHead(HttpURLConnection con) 0pSqk/
{ |G5Me
for(int i=1;;i++) @} 61D
{ F .(zS(q
String header=con.getHeaderFieldKey(i); ;eG,T-:
if(header!=null) L%[om c?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uH}cvshv
Utility.log(header+" : "+con.getHeaderField(header)); o0nKgq'w|x
else Ri}n0}I
break; $LLy#h?V]
} >^8=_i !
} =c-,uW11[
1?6;Oc^
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public void splitterStop() f\ wP}c'
{ d{UyiZm\
bStop = true; ^b{w\HZ
} Wn(pz)+Y
c({V[eGY
JO4rU- n
} Pw^lp'dO
ZR~ *Yofy
wz-#kH5?
/* HbRDa
**FileAccess.java p/4\O
*//文件访问(定位，写) '\$2+*
package NetFox; 4v"9I(
import java.io.*; <Ct b^4$
3J2j5N:g
ZYy,gu<
public class FileAccessI implements Serializable{ ,Qgxf';+$
>Jl(9)e
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ix;9D'^}
RandomAccessFile oSavedFile; W?5u O
long nPos; N{}XHA
f_*Bd.@
~>af"<
public FileAccessI() throws IOException eB`7C"Z
{ K[%)_KW
this("",0); ,DN>aEu1
} ;TAf[[P
HQ8oOn
nQ/R,+6h
public FileAccessI(String sName,long nPos) throws IOException 4,o|6H
{ -.8 nEO3
oSavedFile = new RandomAccessFile(sName,"rw"); mCa[?
this.nPos = nPos; }{J5)\s9
oSavedFile.seek(nPos); l .8@F
} 6dG:3n}
##gq{hgjb$
a&6e~E$K2
public synchronized int write(byte[] b,int nStart,int nLen) 9V]\,mD=
{ =K6aiP$Ft
int n = -1; [xF(t @p
try{ qRXb9c
oSavedFile.write(b,nStart,nLen); ]-Z="YPY
n = nLen; _;] 3w
} X~DI d
catch(IOException e) SjT8eH #
{ 3d qj:4[f
e.printStackTrace (); ,k*g`OTW
} l2))StEm
WUQlAsme
YQyf:xJ
return n; ~kdxJP"
} 5]/i[T_
bk@F/KqL
~bSPtH ]6d
} GA,6G [E
wf4?{H
prf
/* CNCWxu
**SiteInfoBean.java Cv@ZzILyoK
*/ .w/_Om4T*b
package NetFox; K:!|xr(1d
`'Fz:i
A4lh`n5%
public class SiteInfoBean { -6(u09mb_
)z'LXy8
|K(j}^1k
private String sSiteURL; //Site's URL sb"etc`w%-
private String sFilePath; //Saved File's Path y^vB_[6l
private String sFileName; //Saved File's Name -nbo[K
private int nSplitter; //Count of Splited Downloading File i%m]<yElm
kW"6Gc&HUN
;++CMTza]
public SiteInfoBean() 5&WYL
{//nSplitter的缺省值为5 ).[Mnt/Ft
//default value of nSplitter is 5 #HjiE
this("","","",5); Ww9%6 #it
} &,pL3Qos
KLpe!8tAe
Xx~za{p
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) FOB9J.w4
{ D$W&6'
sSiteURL= sURL; 26yjQ
sFilePath = sPath; x>5"7MR`
sFileName = sName; /&g5f4[|p
this.nSplitter = nSpiltter; *~~&*&+
2R:I23[#B
> YHwWf-
} O s*B%,}
h rL_. 4
0_d,sC?V
public String getSSiteURL() ;Kq/[$~0
{ NwH`t#zd
return sSiteURL; 3urL*Fw,
} NA5AR*f'
B3Id}[V
Xr54/.{&@
public void setSSiteURL(String value) fAHK<G4
{ @D<q=:k
sSiteURL = value; mJBvhK9%
} s68&AB
%E\&9,
L0\97AF
public String getSFilePath() 0G-M.s}A
{ Jx#r
return sFilePath; `Zn2Vx
} 9[<,49
6#egy|("nF
5^"T`,${
public void setSFilePath(String value) ~f/nq/8
{ jSLNQ
sFilePath = value; }pP<+U
} 9G7lPK
+8tdAw
86[/NTD<-
public String getSFileName() 9,h'cf`F
{ ?T+Uu
return sFileName; fv1pA+zN[
} 6$"gm$3O]
o)_;cCr)q
?LP&VU1
public void setSFileName(String value) 7_,)"J2^
{ "c[ D0{\{
sFileName = value; 9$-V/7@)
} DOi\DJV!
C_>dJYM
yDwG,)m 4s
public int getNSplitter() ;t'~
{ 3B }Oy$p
return nSplitter; %O$4da"y
} u`Ew^-">
2=X\G~a
?NV3]vl
public void setNSplitter(int nCount) $S~e"ca1
{ jD@KG
nSplitter = nCount; 2rS|V|d
} y#[PQT
} obUX7N
i3T]<&+j5
dW3q
/* 1aC?*,e?
**Utility.java 7x *]
*/ !<psK[
package NetFox; o<\CA[
TCW[;d
`(j}2X'[
public class Utility { Vx1xULdY
}"?v=9.G
?eUhHKS5
public Utility() aE0yO#=
{ Iu`B7UOF
`WDN T0@M
_e/>CiN/
} 'je=.{[lWt
7<W7pXDp
//线程睡眠 wO6`Ap t1:
public static void sleep(int nSecond) Etk`>,]Y>y
{ ^rd]qii"
try{ &%QtUPvr9
Thread.sleep(nSecond); ISy\g`d`C
} &5fM8Opkd
catch(Exception e) _<?lP$Xr
{ <^}{sdOyu
e.printStackTrace (); mT8")J|2
} :Gyv%>.
} ^P&)2m:s
Z!Y ^iN
//日志 QO;W}c:N
public static void log(String sMsg) V\nQHzjF<6
{ @+LZSd+I
System.err.println(sMsg); cwK6$Ax
} L&td4`2y
]|cL+|':y
v1h*/#
public static void log(int sMsg) K8 Y/sHl
{ vas
System.err.println(sMsg); Xj:?V;
} Ip}(!D|
} u@v0I$
~`Q8)(y<#$
^cO^3=
/* &PRu[!
**TestMethod.java <&3qFK*9r
*/ Q<$I,C]
package NetFox; S:qML]RO
{}ks[%,_\
/"d5<B`%
public class TestMethod { 9OYsI
+R}(t{b#
> <WR]`G
public TestMethod() ;qT~81
{ ///xx/weblogic60b2_win.exe KD]8n]c
try{ %a-:f)@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8NLTq|sW
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }a= &o6=
SiteFileFetch fileFetch = new SiteFileFetch(bean); /`yb75
fileFetch.start(); =k]RzeI
} I13nmI\
catch(Exception e){e.printStackTrace ();} !Fa2F~#h
q=8I0E&q
CrHH Ob
} ;5 W|#{I
1-C 2Y`
KL]@y!QU
public static void main(String[] args) d,j"8\@
{ |ToCRM
new TestMethod(); A!}Wpw%(/
} :~JgB
} e6{}hiM
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