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)); 2I=4l
} ms&5Bq+9
for(int i=0;i<nEndPos.length-1;i++) KxJDAP
{ LsMq&a-j2
nEndPos = nStartPos[i+1]; p4uObK,
} *&_(kq z'1
nEndPos[nEndPos.length-1] = nFileLength; +r"fv*g"
} 6: R1jF*eG
} ^#h ;bX#
Fkqw#s(T
:9>U+)%
//启动子线程 7/=r-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .q 4FGPWz
for(int i=0;i<nStartPos.length;i++) uXGAcUx(
{ loyhNT=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a|dn3R>vX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +9;6]4
nStartPos,nEndPos,i); Ni;jMc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EUPc+D3
fileSplitterFetch.start(); e/)Vx'd`+
} T%TO?[cN
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oSR;Im<2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); sw(|EZ7F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c/-'^+9
nEndPos = " + nFileLength); }mk z_P(Z
// fileSplitterFetch[nPos.length-1].start(); ( ~>-6Nb 5
*MCkezW7{
tg2+Z\0)4g
//等待子线程结束 -?)z@Lc
//int count = 0; 0}>p)k3&A
//是否结束while循环 2tp95E`(O
boolean breakWhile = false; *u>[
<{HV|B7
wX@g>(
while(!bStop) c5eimA%`
{ Fe 78YDx?
write_nPos(); Og2w]B[
Utility.sleep(500); B1U7z1<
breakWhile = true; .T~Oc'wGo
kKVNE hTp
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for(int i=0;i<nStartPos.length;i++) E@@XWU21;N
{ U]E~7C
if(!fileSplitterFetch.bDownOver) `y&2Bf
{ T' )l
breakWhile = false; ir;az{T#U
break; s<LYSrd
} (=Lx9-u
} N/B-u)?\:
if(breakWhile) gF|u%_y-qt
break; QIcc@PGT9a
u>03l(X6f
=kW7|c5Z
//count++; #/>OW2Ny
//if(count>4) 2J6(TrQ
// siteStop(); s%l^zA(
} #ChF{mh
q+9c81b
Q,>]f@m
System.err.println("文件下载结束！"); a7fn{VU8
} _$gP-J
catch(Exception e){e.printStackTrace ();} S1*xM
} P[gYENQ
kK]L(ZU+
T$Rf
//获得文件长度 to] ~$~Q|>
public long getFileSize() }}d,xI
{ WSx0o}
int nFileLength = -1; $?|$uMIafp
try{ ekSSqj9";
URL url = new URL(siteInfoBean.getSSiteURL()); p}a0z?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^#z*
httpConnection.setRequestProperty("User-Agent","NetFox"); e6'y S81
-h&KC{Xab
rhwjsC6
int responseCode=httpConnection.getResponseCode(); {=T9_c
if(responseCode>=400) 843O}v'
{ lMb&F[KJ7
processErrorCode(responseCode); -=4:qQEw
return -2; //-2 represent access is error mA\}zLw+r9
} C.=[K_
ggzcANCD<
AKUmh
String sHeader; B d?{ldg
3TnrPO1E
<L<d_
for(int i=1;;i++) 5wm(gF_t
{ &jE@i#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y-a3
//Utility.log(in.readLine()); Zopi;O J
sHeader=httpConnection.getHeaderFieldKey(i); #J*hZ(Pq
if(sHeader!=null) 6F3FcUL
{ d01]5'f?o
if(sHeader.equals("Content-Length")) t$ 3/ZTx
{ QWAtF@qTV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s{T6qJ
break; SH1)@K-
} Gxh1wqLR
} CdNb&Nyz
else #HmZe98[%
break; [|APMMYK1
} oYrg;]H
} ze#r/j;sw
catch(IOException e){e.printStackTrace ();} e#|YROHf
catch(Exception e){e.printStackTrace ();} (Ujry =f
mBg$eiGTB
tE;c>=>t
Utility.log(nFileLength); DDp\*6y3l
1HBXD\!
:#Nrypsu
return nFileLength; Nu7lPEM
} 4)E$. F^
g,}_&+q:.M
}\aJ%9X02
//保存下载信息（文件指针位置） <,Pk
private void write_nPos() .%+y_.l
{ D[p`1$E-1v
try{ o6)U\z
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]YKxJ''u
output.writeInt(nStartPos.length); FZ=xy[q]~
for(int i=0;i<nStartPos.length;i++) =nE^zY2m%
{ kuW^_BROJ
// output.writeLong(nPos); #9p|aS\
output.writeLong(fileSplitterFetch.nStartPos); r5'bt"K\>
output.writeLong(fileSplitterFetch.nEndPos); ! +XreCw
} F%G} >xn
output.close(); v8 pOA<s
} I"2*}v|
catch(IOException e){e.printStackTrace ();} 0K^?QM|S
catch(Exception e){e.printStackTrace ();} K5}0!_)G
} sc$I,|d2
@ x5LrQ_`r
O#x=iZI
//读取保存的下载信息（文件指针位置） @*-t.b2k
private void read_nPos() ;><m[l6
{ aQglA
try{ P$*9Z@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WSOz^]
int nCount = input.readInt(); M^jEp
nStartPos = new long[nCount]; -qdt$jIM
nEndPos = new long[nCount]; L4or*C^3
for(int i=0;i<nStartPos.length;i++) B PG&R
{ Pd;Gc@'~
nStartPos = input.readLong(); 0@kL<\u
nEndPos = input.readLong(); CX#d9 8\b
} :*WiswMFm
input.close(); w7b\?]}@
} WlmkM?@
catch(IOException e){e.printStackTrace ();} ;2l|0:
catch(Exception e){e.printStackTrace ();} W?D-&X^ny
} nG0R1<
(0^ZZe`#j
)_SpY\J
private void processErrorCode(int nErrorCode) p;.M.
{ 0n*D](/NK
System.err.println("Error Code : " + nErrorCode); !TLJk]7uC
} )F,z pGG
cr~.],$Om
U[W &D%'
//停止文件下载 dK>sHUu
public void siteStop() v:]z-zU
{ S9dXkd
bStop = true; W}@IUCRs
for(int i=0;i<nStartPos.length;i++) q@vqhE4
fileSplitterFetch.splitterStop(); jR>`Xz
Y]bS=*q
>Ft)v
} 5Kw?#
} i7%`}t
//负责部分文件的抓取 U;t1 K
**FileSplitterFetch.java %BF,;(P
*/ nB6 $*'
package NetFox; O2"5\@HfE
Lwn
"D'"uMS`H
import java.io.*; 61](a;Di
import java.net.*; 8yk4#CZ
L5r02VzbD
>35W{d
public class FileSplitterFetch extends Thread { H`1q8}m
=:'\wx X
H h35cj
String sURL; //File URL __}ut+H^5p
long nStartPos; //File Snippet Start Position l"/E,X
long nEndPos; //File Snippet End Position HJJ;gTj
int nThreadID; //Thread's ID O~mQ\GlW
boolean bDownOver = false; //Downing is over 2WC$r8E
boolean bStop = false; //Stop identical 17-B'Gl!<%
FileAccessI fileAccessI = null; //File Access interface ; *\xdg{d
Z?u}?-b1\H
izs=5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RoNE7|gF:
{ 6B+?X5-6DH
this.sURL = sURL; nWA>u J5
this.nStartPos = nStart; w@pJ49
this.nEndPos = nEnd; _ Y7Um
nThreadID = id; g)7@EU2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X0]{8v%
} k/1S7X[
hDXaCift
[,(+r7aB
public void run() vIf-TQw
{ MV]`[^xQ5
while(nStartPos < nEndPos && !bStop) U9jdb9 |
{ {.ypZ8JU
(__$YQ-
'I$kDM mwh
try{ \>x1#Vr>#V
URL url = new URL(sURL); RK=Pm7L:`y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Iw?*y.z|
httpConnection.setRequestProperty("User-Agent","NetFox"); 0#4A0[vV
String sProperty = "bytes="+nStartPos+"-"; \>||
httpConnection.setRequestProperty("RANGE",sProperty); 2_}oOt?qiM
Utility.log(sProperty); 3)I]bui
@saK:z
@WNqD*)1
InputStream input = httpConnection.getInputStream(); Gn<0Fy2
//logResponseHead(httpConnection); 5p6/dlN-a
H4W!Md
'2 Y8
byte[] b = new byte[1024]; o`G6!
int nRead; -ijzo%&qA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q;*'V9#
{ ESUO I
nStartPos += fileAccessI.write(b,0,nRead); "Mz#1Laby`
//if(nThreadID == 1) =cO5Nt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IwRP,MQ~
} [5tvdW6Z&
A1r%cs
%J Jp/I
Utility.log("Thread " + nThreadID + " is over!"); K+"3He
bDownOver = true; ;A4j_8\[
//nPos = fileAccessI.write (b,0,nRead); N3N~z1x0h
} gu:vf/
catch(Exception e){e.printStackTrace ();} F{^\vFp
} Z_fwvcZ?05
} P^!g0K
,:2Z6~z{
)O5@R
//打印回应的头信息 :{4C2qK>
public void logResponseHead(HttpURLConnection con) \;KSx3o
{ [ r
for(int i=1;;i++) $41<ldJ
{ "?<(-,T
String header=con.getHeaderFieldKey(i); /GX>L)
if(header!=null) ^4NRmlb
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .)=*Yr M
Utility.log(header+" : "+con.getHeaderField(header)); 9yaTDxB>
else TQb@szp:|
break; rIb~@cR)
} y4l-o
} +~ Hb}0ry
V^4v`}Wgx
;u[:J
public void splitterStop() d2d8,Vg
{ &n6L;y-
bStop = true; E0/>E
} #-PMREgO
|?ZU8I^vW
mln4Vl(l2M
} WrcmC$ff
+ K`.ck
crOSr/I$
/* 5*+DN U@
**FileAccess.java 'J3yJ{
*//文件访问(定位，写) !Z |_3
package NetFox; 4_ypFuS^
import java.io.*; _>n)HG
yf!7 Q>_G^
zyO=x4U8
public class FileAccessI implements Serializable{ a6cU<(WDeh
y10W\beJ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .c&&@>m@.
RandomAccessFile oSavedFile; tzfyS#E
long nPos; M$.bC0}T
60]VOQku
|&xaV-b9W
public FileAccessI() throws IOException wN10Drc
{ SvQ|SKE':
this("",0); SjpCf8Z(
} *aC[Tv[-P
[s`B0V`04
[[]yQ "
public FileAccessI(String sName,long nPos) throws IOException -G@uB_Cs
{ 6P}?+ Gc
oSavedFile = new RandomAccessFile(sName,"rw"); ~k-'
this.nPos = nPos; %rJDpB{
oSavedFile.seek(nPos); @*~yVV!5
} A,tg268
J[r_ag
l)o!&]2
public synchronized int write(byte[] b,int nStart,int nLen) GD)paTwO<
{ xb%Q[V_m
int n = -1; 7w" !"W#
try{ vea{o35!
oSavedFile.write(b,nStart,nLen); lR7;{zlSf'
n = nLen; _ Pzgn@D
} H! 5Ka#B
catch(IOException e) 8+dsTX`|S
{ JP0aNu
e.printStackTrace (); -^yc<%U
} fZr{x$]N0
a%BC{XX
/3k[3
return n; uL-kihV:-
} &=*1[j\
=,q/FY:
[%R?^*]
} re/u3\S
<9"@<[[,
t(V2
/* #<B?+gzFM{
**SiteInfoBean.java H.]V-|U
*/ T^vo9~N*
package NetFox; E;4B!"Q8
F.x7/;
Rf8ZH
public class SiteInfoBean { r>|S4O
X_nbNql
Oi& 9FS
private String sSiteURL; //Site's URL Sin)]zG~0
private String sFilePath; //Saved File's Path UMBeY[?
private String sFileName; //Saved File's Name xi.?@Lff
private int nSplitter; //Count of Splited Downloading File #:yAi_Ct
N#jUqm
COm^ti-p
public SiteInfoBean() 3!@&7@p
{//nSplitter的缺省值为5 #y7MB6-
//default value of nSplitter is 5 +PLJ
this("","","",5); RA!m,"RM
} mt0v (
i <gt`UCO
04=RoYMM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^`dMjeF
{ T,a{mi.hNR
sSiteURL= sURL; 0S;Ipg
sFilePath = sPath; t4d/%b~{:U
sFileName = sName; YGM7?o
this.nSplitter = nSpiltter; p=eSJ*
"k
2B6u) 95
} *^7^g!=z2
|}e"6e%
uEr.LCAS
public String getSSiteURL() ~H?v L c;>
{ #Pz'-lo
return sSiteURL; CE
} muF&t'k
ow 6\j:$?
fj(WHL
public void setSSiteURL(String value) @ YWuWF
{ 2Hx*kh2
sSiteURL = value; yB*aG
} /8`9SS
@>~S$nw/
UHi^7jQ
public String getSFilePath() ]Hi1^Y<
{ zK1\InP
return sFilePath; oa7 N6
} 5syzh S
ASMItT
w""u]b%:r
public void setSFilePath(String value) -gC%*S5&
{ 'cQ`jWZQ
sFilePath = value; ,g?M[(wtc
} ujX\^c
>b3IZ^SB#$
>dF #1
public String getSFileName() r z@%rOWV
{ hZUS#75M5
return sFileName; F{7 BY~d
} e*( _Cvxp
=yqg,w&Q
G+C{_o#3
public void setSFileName(String value) 6OPNP0@r
{ "4smW>f:%
sFileName = value; {BAZ`I
} Of-gG~
ci(BPnQ
-ECnX/ "
public int getNSplitter() 98<^!mwF
{ c[OQo~m$
return nSplitter; M5`m5qc3
} /n,a0U/
6w{""K.{
cY~lDLyB
public void setNSplitter(int nCount) uSCI
{ O,J,Q|`H&
nSplitter = nCount; Cd p_niF
} !g>mjD
} d]=>U^K
_A]~`/0;`
.:;q8FL/
/* Pm24;'
**Utility.java J(XK%e[8
*/ nu|odP
package NetFox; zCwb>v
F>@z&a}(
d+eb![fi
public class Utility { 4HXNu,T'
`wLmGv+V
=E~SaT
public Utility() >6;RTN/P2
{ _@|_`5W
OW> >6zM
Gn10)Uf8X
} yaX%<KBa\
><6g-+*k
//线程睡眠 %=v<3
public static void sleep(int nSecond) *;.:UR[i
{ U.WMu%
try{ k}{K7,DM
Thread.sleep(nSecond); n^epC>a"b
} d k|X&)xTJ
catch(Exception e) [vCZD8"Y8
{ U:IeMf-;
e.printStackTrace (); I)G.tJZ e
} 3_ =:^Z
} +n8,=}
O}Do4>02
//日志 KR4RIJZ_t
public static void log(String sMsg) yLt?XhRlp
{ ]b&qC (
System.err.println(sMsg); e=Kr>~q=
} cXOb=
)jRaQ~Sm
T=cb:PD{%
public static void log(int sMsg) nQ'AB~ Do
{ !un_JZD
System.err.println(sMsg); pQ+4++7ID
} j%*<W> O
} +(hr5
P$;_YLr
vnz}Pr! c
/* jCt[I5"+z
**TestMethod.java 9n".Q-V;k
*/ ;|K(6)
package NetFox; Aa%ks+1
\V<deMb=
{D&:^f
public class TestMethod { \RTXfe-`
1FC1*7A[
a,p7l$kK
public TestMethod() ch}(v'xv(
{ ///xx/weblogic60b2_win.exe qZP>h4
try{ #1f8A5<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gCS%J40r
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F(:]lM|
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3gmu-tv
fileFetch.start(); ps?B;P
} .gHL(*1P
catch(Exception e){e.printStackTrace ();} ,b8B)VZ?
b;sjw5cm_
v~HfA)#JK
} -U_<:
YJrZ
X?.LA7)CK
public static void main(String[] args) E|^~R}z)
{ 1Xu^pc
new TestMethod(); %(wa~:m+S-
} qdVExO&
} L~(`zO3f
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