http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); b9H(w%7ucU
} Q<sqlh!h
for(int i=0;i<nEndPos.length-1;i++) h&4s%:_4
{ @.;+WQE
nEndPos = nStartPos[i+1]; F5?S8=i
} ~&Z>fgOTJ
nEndPos[nEndPos.length-1] = nFileLength; )^:H{1'
} _c-3eQ1
} [Uup5+MCv
z:Am1B
cSt)Na~C
//启动子线程 < $zJi V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; oN032o?S
for(int i=0;i<nStartPos.length;i++) JBY.er`6C
{ 217G[YE-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Lu#qo^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %+*=Vr
nStartPos,nEndPos,i); TpU\IQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |=;hQ2HyF
fileSplitterFetch.start(); P~ObxY|
} ]p!{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3)G~ud
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _xKn2?d8g
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [c{\el9H
nEndPos = " + nFileLength); a_Y<daRO
// fileSplitterFetch[nPos.length-1].start(); >oW]3)$4S
UA<Fxt
%IsodtkDu
//等待子线程结束 bRvGetX
//int count = 0; -,8LL@_
//是否结束while循环 HzTmNm)
boolean breakWhile = false; bYsX?0T!p
9KVJk</:n
atyvo0fNd
while(!bStop) sS-dHa
{ kqBZsfF
write_nPos(); x9YQd69
Utility.sleep(500); TIGtX]`
breakWhile = true; ^aL> /'Y#|
9/5EyV
TfA;4^
for(int i=0;i<nStartPos.length;i++) h56s~(?O
{ mP ^*nB@,
if(!fileSplitterFetch.bDownOver) pR~"p#Y
{ 7FP @ vng
breakWhile = false; \ id(P3M
break; ~*G}+Ur$2
} bKPjxN?!9
} _dn*H-5hO
if(breakWhile) G)7J$4R
break; ;0E[ ; L!
4' <y
}+ TA+;
//count++; 2H`;?#Uq:
//if(count>4) @XX7ydG5
// siteStop(); [AAIBb+U
} eLop}*k
{=kW?
[{rne2sA
System.err.println("文件下载结束！"); [[8h*[:
} -<gQ>`(0
catch(Exception e){e.printStackTrace ();} OMN|ea.O
} ^p #bxN")
(I(k$g[>
LfG$?<}hR
//获得文件长度 5?gZw;yiv%
public long getFileSize() ;F>I+l_X
{ Ya,(J0l
int nFileLength = -1; yg@}j
try{ >U')ICD~
URL url = new URL(siteInfoBean.getSSiteURL()); A/*h[N+2!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T ^z Mm
httpConnection.setRequestProperty("User-Agent","NetFox"); .[X"+i\
PhC{Gg
.1?7)k v
int responseCode=httpConnection.getResponseCode(); JWs?az
if(responseCode>=400) ,zrShliU
{ qt#4i.Iu+
processErrorCode(responseCode); N`i`[ f
return -2; //-2 represent access is error Nx4X1j?-n
} 3`\)Qm
JQWW's}
+\`t@Ht#
String sHeader; Y@M l}43
$^"_Fox]A\
4xNzhnp|
for(int i=1;;i++) vE+OL8V
{ xDBHnr}[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +S>}<OE
//Utility.log(in.readLine()); IpMZ{kJlv`
sHeader=httpConnection.getHeaderFieldKey(i); @](\cT64i3
if(sHeader!=null) f:K`MW
{ T@H2[ 7[;
if(sHeader.equals("Content-Length")) T~'9p`IW
{ * E3 c--
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O1K~]Nt
break; z;EnAy{9
} *Ad7GG1/u
} p~THliwd
else w~(x*R}
break; aF\?X&|
} 1z[GYRSt
} 5Pl~du
catch(IOException e){e.printStackTrace ();} :-kXZe
catch(Exception e){e.printStackTrace ();} g"Z X1X
5U/1Z{
(e;9,~u)
Utility.log(nFileLength); A?xb u*zV,
NCM&6<_
%Sdzr!I7*
return nFileLength; C=/nZGG
} h8!;RN[
jHx<}<
:J}@*>c
//保存下载信息（文件指针位置） pQY.MZSA
private void write_nPos() 6uijxia
{ 61J01(+|
try{ R]Q4+
output = new DataOutputStream(new FileOutputStream(tmpFile)); Q`}n;DV
output.writeInt(nStartPos.length); oGLSk(T&I
for(int i=0;i<nStartPos.length;i++) L.xzI-I@D
{ FT* o;&_QS
// output.writeLong(nPos); ]{[VTjC7rY
output.writeLong(fileSplitterFetch.nStartPos); 7^~pOFdH
output.writeLong(fileSplitterFetch.nEndPos); WqC6c&NM
} &:` 7
output.close(); fxQN
} [-sE:O`yt
catch(IOException e){e.printStackTrace ();} F=hfbCF5x
catch(Exception e){e.printStackTrace ();} ^J>jU`)CJ
} M,Px.@tw.
?~aM<rcZ
<oSk!6*
//读取保存的下载信息（文件指针位置） e.0vh?{\
private void read_nPos() )]%GNdU
{ %Ya-;&;`
try{ OwQ 9y<v
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); V\kf6E
int nCount = input.readInt(); 1Ly?XNS
nStartPos = new long[nCount]; J|Lk::Ri
nEndPos = new long[nCount]; U"xI1fg%b
for(int i=0;i<nStartPos.length;i++) Y1 i!
{ VPf*>ph=
nStartPos = input.readLong(); kvdzD6T 9
nEndPos = input.readLong(); HPT9B?^
} Ox&g#,@h
input.close(); O;:8mm%(
} t9PS5O ;
catch(IOException e){e.printStackTrace ();} -[a0\H
catch(Exception e){e.printStackTrace ();} (0"9562
} f$k#\=2%
KTk%Np
COj50t/
private void processErrorCode(int nErrorCode) EPr{1Z
{ u:N/aaU=
System.err.println("Error Code : " + nErrorCode); X63DBF4A
} /wCeeG,<
;2}0Hr'|
Xig+[2zS
//停止文件下载 DnaG$a<
public void siteStop() ~?6V-m{>#
{ P7E}^y`e
bStop = true; KI$?0O
for(int i=0;i<nStartPos.length;i++) U;6~]0^K
fileSplitterFetch.splitterStop(); $RKd@5XP
~/\;7E{8!
C|W_j&S65
} lV$U!v:b
} J C1T033 r
//负责部分文件的抓取 Os8]iNvW\
**FileSplitterFetch.java 6yTL7@V|B
*/ u3 ?+Hu|*T
package NetFox; ygUvO3Z
?YgK]IxD
=o_d2Ak
import java.io.*; bR*T}w$<
import java.net.*; c.,:rX0S
;myu8B7&
w_,.
public class FileSplitterFetch extends Thread { KL.{)bi
`-s+ zG
>}O1lsjW:z
String sURL; //File URL g=b[V
long nStartPos; //File Snippet Start Position n1uJQt
long nEndPos; //File Snippet End Position / vje='[!
int nThreadID; //Thread's ID jfqWcX.X=
boolean bDownOver = false; //Downing is over =[t([DG
boolean bStop = false; //Stop identical U`<EpO{j|
FileAccessI fileAccessI = null; //File Access interface 52l|
Q-O:L
>eAlz4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A~nq4@uj
{ (rZq0*
this.sURL = sURL; s4MP!n?gB
this.nStartPos = nStart; YV{^S6M
this.nEndPos = nEnd; l%fnGe` _
nThreadID = id; M29[\@zL
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $hndb+6q
} *M+:GH/5
/ )5B
'$1-A%e$1
public void run() #dW$"u
{ 1xM&"p:
while(nStartPos < nEndPos && !bStop) >\}2("bv
{ Gu*;z% b2
EW#.)@-
wzo-V^+q
try{ \)y5~te*
URL url = new URL(sURL); Jev@IORN\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jW2z3.w
httpConnection.setRequestProperty("User-Agent","NetFox"); ] =>vv;L
String sProperty = "bytes="+nStartPos+"-"; ;13lu1
httpConnection.setRequestProperty("RANGE",sProperty); ,a^_ ~(C
Utility.log(sProperty); ?PyI#G
%tUJ >qYU
nF A7@hsm
InputStream input = httpConnection.getInputStream(); _u{D#mmO
//logResponseHead(httpConnection); JsfbY^wz
_QY0j%W
6prN,*k5
byte[] b = new byte[1024]; JWMIZ{/M
int nRead; $vGlZ<3g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'cH),~ z
{ (X>r_4W$
nStartPos += fileAccessI.write(b,0,nRead); I|Z5*iXqCm
//if(nThreadID == 1) d<7xSRC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DNki xE*
} 1__p1
En5I
xOTm-Cm9L
Utility.log("Thread " + nThreadID + " is over!"); mjBXa
bDownOver = true; [.Kia >
//nPos = fileAccessI.write (b,0,nRead); ;K$E;ZhPN
} !WVF{L,/I
catch(Exception e){e.printStackTrace ();} VEb}KFyP
} ix7N q7!N
} P-^Z7^o-bX
3.R?=npA
5"XcVH4g
//打印回应的头信息 qr<5z. %
public void logResponseHead(HttpURLConnection con) Gt6$@ji4u
{ *QjFrw3
for(int i=1;;i++) P}?,*'b
{ A`X$jpAn&
String header=con.getHeaderFieldKey(i); k*z)AR
if(header!=null) 3TtnLay.k
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5Z`f)qE
Utility.log(header+" : "+con.getHeaderField(header)); jw(v08u >
else _h@e.BtDs
break; !n)2HDYhx,
} zJdlHa{
} \i`/k(
?LvZEiJ
z4{|?0=C
public void splitterStop() HlI*an
{ <5C3c&sds
bStop = true; G.T}^xHmL
} kCN9`9XI{
fS!%qr
o1I{^7/
} ;znIY&Z
8Jxo;Y
a#j0N5<Nl
/* kS=OX5
**FileAccess.java ~p8-#A)X,)
*//文件访问(定位，写) [gH vI
package NetFox; nJ'O(Wh,)
import java.io.*; }v@w(*)h:
WBTX~%*U
hQ8/-#LO_
public class FileAccessI implements Serializable{ P) GBuW
oh#6>|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `4w0*;k;
RandomAccessFile oSavedFile; hofZpM
long nPos; KcNEB_i
Ngh9+b6[
6^UeEmjc
public FileAccessI() throws IOException /-G;#Wm
{ 'iUfr@
this("",0); Tv~<W4
} 9s5CqB
(K^9$w]tf
J%3S3C2*m
public FileAccessI(String sName,long nPos) throws IOException K^s!0[6
{ duT2:~H2
oSavedFile = new RandomAccessFile(sName,"rw"); MCL5a@BX)
this.nPos = nPos; TQ>kmHWf/
oSavedFile.seek(nPos); CKNH/[ZR,
} rv:,Os_
s 6vsV
YX!%R]c%
public synchronized int write(byte[] b,int nStart,int nLen) i&{8a3B
{ dl(cYP8L
int n = -1; rc9 \
try{ " 0K5 /9
oSavedFile.write(b,nStart,nLen); i nF&Pv
n = nLen; jJ|u!a
} r?[PIf
catch(IOException e) 1ciP+->$
{ IkL|bV3E0
e.printStackTrace (); 'zi5ihiT
} sAC1Pda
G5bi,^G7
Gvl-q1PVC
return n; K,?M5n '
} ZMy7z|
.+|G`*1<i
9V[|_
} p,$1%/m
:$dGcX}
>umcpkp-h
/* l3b$b%0'
**SiteInfoBean.java .oN<c]iqE
*/ >2vl & (
package NetFox; r >u0Y
=pN?h<dc
dkLc"$(O
public class SiteInfoBean { bX=ht^e[
v3Te+oLg
cQ1oy-paD
private String sSiteURL; //Site's URL !ck=\3pr
private String sFilePath; //Saved File's Path ol:,02E&
private String sFileName; //Saved File's Name vn6/H8
private int nSplitter; //Count of Splited Downloading File ?R;5ErZ
B`iQN7fd
c{V0]A9VF
public SiteInfoBean() 'nBJ[$2^
{//nSplitter的缺省值为5 9IN=m 5
//default value of nSplitter is 5 .G?7t6A
this("","","",5); )p(5$AR7
} {KdC51"Nv
4~ZQsw`
C W7E2 ^P$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !M)!
{ q !EJs:AS
sSiteURL= sURL; lk2F]@_kJH
sFilePath = sPath; tA3]6SIK@
sFileName = sName; :BC0f9
this.nSplitter = nSpiltter; ` {k>I^Pg
^qIp+[/'
J,4]du$
} ?G*XZ0u~
4ME8NEE
A\i/@x5#
public String getSSiteURL() o-lb/=K+
{ /FkLZm
return sSiteURL; d[kb]lC
} 1AjsAi,7;2
jE&kN$.7j
HP3~.1Sp
public void setSSiteURL(String value) xX{uDMYa;
{ InH R>,
sSiteURL = value; k#c BBrY
} )>\J~{
&oWWc$
]i8K )/
public String getSFilePath() "SNsOf
{ S/G,A,"c
return sFilePath; 0`h[|FYV
} zt[TShD^
E:D1ZV
@1*lmFq'kV
public void setSFilePath(String value) oeDsJ6;
{ J.$<Lnt>u
sFilePath = value; ngsax1xO
} (|'w$
FT[oM<M\Xd
s|pb0
public String getSFileName() d;mQ=k 1
{ Jtd@8fVi
return sFileName; j /)cdP
} Rb#Z'1D'G
Ook3B
\#LKsQa
public void setSFileName(String value) cuq7eMG6z
{ (PsA[>F
sFileName = value; "sAR<5b
} L]K*Do
D'fP2?3FK
g~FB&U4c
public int getNSplitter() ^nbze
{ P^rSpS9
return nSplitter; M\\TQ(B
} ~q4DePVE
^b-H
&0(2Z^Z>fw
public void setNSplitter(int nCount) @]3(l
{ 6WceDY
nSplitter = nCount; k`oXo%
} + {a
} "Y(S G
JO :m: M
7c %@2
/* ~gI%
**Utility.java a Q`a>&R0
*/ ;lYO)Z`3\
package NetFox; }[LK/@h
C>T6{$xkC
Z]w_2- -
public class Utility { ^jf$V#z0/
PDD` eK}Fj
nJ*NI)
public Utility() *\S>dhJ4
{ Qbv)(&i#~
*2:)Rf
(a^F`#]
} fi bR:8
}Ecm
//线程睡眠 V{d"cs>9
public static void sleep(int nSecond) PU-~7h+$
{ LR9'BUfFv
try{ ^+GN8LUs
Thread.sleep(nSecond); $<ZX};/D
} =WO{h48]
catch(Exception e) TS UN(_XGW
{ Llk`
e.printStackTrace (); Z<&: W8n
} 2B!nLLCp+
} Uj!L:u2b
57[O)5u.+
//日志 m|f|u3'z$
public static void log(String sMsg) %H}+'.8
{ 7kJ,;30)
System.err.println(sMsg); 0hNc#x6
} [,1j(s`N5
,9A[o`b
Nm;ka&'
public static void log(int sMsg) jXW71$B
{ ~+T~}S
System.err.println(sMsg); ~z< ? Wh
} i,)kI
} .5I1wRN49
CX1'B0=\r
SQz>e
/* |J6CH87>
**TestMethod.java h[lh01z
*/ 5k\61(*s
package NetFox; BRW
-AffKo
a{-}8f6
public class TestMethod { YE^|G,]
3F4I{L
TI*uNS;-
public TestMethod() 35,SPR
{ ///xx/weblogic60b2_win.exe +Uk/Zg w^
try{ S&QZ"4jq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ].Et&v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >yL8C:J9
SiteFileFetch fileFetch = new SiteFileFetch(bean); i4uUvZf
fileFetch.start(); QzV:^!0J
} $:<KG&Br
catch(Exception e){e.printStackTrace ();} Z-/ E$j
aIm\tPbb
r<~1:/F|
} YxsWY7J
e<IT2tv>u
q'1rSK
public static void main(String[] args) WO '33Q(
{ S(rA96n
new TestMethod(); o,X ?
} 7[8PSoo
} ,c7 8O8|
点击下载更多相关资料