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)); R](cko=
} }#2(WHf=<
for(int i=0;i<nEndPos.length-1;i++) 6y "]2UgQk
{ 8C?E1fH\
nEndPos = nStartPos[i+1]; .|Yn[?(
} y2mSPLw
nEndPos[nEndPos.length-1] = nFileLength; F>5b[q6~4
} g[HuIn/
} ^go3F{;4i
oad /xbp@/
$e{[fmx
//启动子线程 x6$3KDQm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8F'm#0
for(int i=0;i<nStartPos.length;i++) s}yN_D+V
{ TA8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OOXP1L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -%Ce
nStartPos,nEndPos,i); =diGuIB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l_8ibLyo
fileSplitterFetch.start(); $~j9{*]5
} \KS.A 4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gm3`/!r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :Rnwyj])
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yhI;FNSf
nEndPos = " + nFileLength); ]rNxvFN*j
// fileSplitterFetch[nPos.length-1].start(); lgD%
t@a&&
:t;i2Ck
//等待子线程结束 -3y
//int count = 0; Oqt{ uTI~
//是否结束while循环 d(@ ov^e-
boolean breakWhile = false; 9Zmq7a E
.>~er?-
U_.}V
while(!bStop) 3lEP:Jp
{ aT+w6{%Z
write_nPos(); /d/]#T[Z9
Utility.sleep(500); i2;,\FI@t%
breakWhile = true; Vg :''!4t2
P}>>$$b\Yi
VR%*8=
for(int i=0;i<nStartPos.length;i++) ,rF!o_7
{ G:wO1f6
if(!fileSplitterFetch.bDownOver) 3OY(L`
{ &}|`h8JA]K
breakWhile = false; J\p-5[E
break; B/^o$i
} H0yM`7[y
} \qlz<
if(breakWhile) sY?wQ:
break; c/:k|x
ZG{#CC=
O3%#Q3c>3
//count++; fZLAZMrM
//if(count>4) 8<32(D{
// siteStop(); B-"F67:
} +(z[8BJl
,U+>Q!$`\^
J, +/<Y!
System.err.println("文件下载结束！"); ~O!E&~
} dWe%6s;
catch(Exception e){e.printStackTrace ();} g!r)yzK
} PnB2a'(^@?
<OJqeUo+*\
$!_}d
//获得文件长度 <b\8<mTr
public long getFileSize() NS TO\36
{ AxF$7J(
int nFileLength = -1; oIMS >&
try{ (H:A|Lw
URL url = new URL(siteInfoBean.getSSiteURL()); fF=tT C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6D`.v@
httpConnection.setRequestProperty("User-Agent","NetFox"); Y=O-^fL
1CM8P3
NR-<2 e3
int responseCode=httpConnection.getResponseCode(); B[ D s?:
if(responseCode>=400) Bn=YGEvz
{ ?'"BX
processErrorCode(responseCode); .3@Pz]\M#>
return -2; //-2 represent access is error 4d}n0b\d
} ~r'ApeI9
='C;^ Bk
@`Dh7Q
String sHeader; IG2z3(j
wuXH'
%da-/[
for(int i=1;;i++) zwP*7u$CH
{ \%%M>4c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;XlCd[J<
//Utility.log(in.readLine()); Ex@}x#3
sHeader=httpConnection.getHeaderFieldKey(i); Ir*{IVvej
if(sHeader!=null) q|IU+r:! 3
{ {a9.0N:4
if(sHeader.equals("Content-Length")) FFmXT/K"/j
{ #J8(*!I
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z@$'fX?~9
break; [a}Idi` K
} 0tPwhJ
} a5d_= :S;
else m5HMtoU
break; p6)6Gcx
} >?G!>kw
} ]@}hyM[D;
catch(IOException e){e.printStackTrace ();} N+H[Y4c?F&
catch(Exception e){e.printStackTrace ();} X &G]ci
"GJ.`Hj
=)N6R
Utility.log(nFileLength); FP0GE
> %Hw008
}*aj&
return nFileLength; qF`]}7"^
} S@~ReRew2
-yu$Mm
vkM_a}%<
//保存下载信息（文件指针位置） CWB<I
private void write_nPos() AUfcf*
{ r&:yZN
try{ U_E t
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3hzz*9/n
output.writeInt(nStartPos.length); I).eQ8:
for(int i=0;i<nStartPos.length;i++) 3RcnoXX_
{ &Wk:>9]Jrb
// output.writeLong(nPos); 5>=4$!`
output.writeLong(fileSplitterFetch.nStartPos); L&]{GNw
output.writeLong(fileSplitterFetch.nEndPos); e ]2GAJLI
} _6]CT0
output.close(); 9'|_1Q.b^
} R?}%rP+^e
catch(IOException e){e.printStackTrace ();} V{\1qg{
catch(Exception e){e.printStackTrace ();} ~4] J'E >
} Vyc
GW7+#
ofgNL .u
//读取保存的下载信息（文件指针位置） SaRn>n\
private void read_nPos() "tDB[?
{ 3u s^\w#
try{ e. E$Ej]w
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H6KBXMYO
int nCount = input.readInt(); /L2.7`5
nStartPos = new long[nCount]; t+,2 p|B
nEndPos = new long[nCount]; 1p<*11
for(int i=0;i<nStartPos.length;i++) 'c >^Aai
{ F&lSRL+v
nStartPos = input.readLong(); 8zjJshE/
nEndPos = input.readLong(); zW[HGI6w
} muhu` k`C
input.close(); -f?,%6(1
} 1].m4vC
catch(IOException e){e.printStackTrace ();} 3S%/>)k
catch(Exception e){e.printStackTrace ();} TpHzf3.I
} p>+Q6o9O
Ksk[sf?J&
F9r|EU#;
private void processErrorCode(int nErrorCode) 'S9jMyZrZ
{ !?K#f?x<?
System.err.println("Error Code : " + nErrorCode); !|mzu1S
} 6;M{suG|
_~2o
f%q ?
//停止文件下载 o,$K=#Iv
public void siteStop() (SA^>r
{ ],'"iVh
bStop = true; 3XncEdy_
for(int i=0;i<nStartPos.length;i++) BJp~/H`vd
fileSplitterFetch.splitterStop(); %P C[-(Q
3aJYl3:0B
:1v.Jk
} )d{fDwrx1
} w5t|C>
//负责部分文件的抓取 .B! Z0
**FileSplitterFetch.java {CX06BP
*/ e=_Ng j)
package NetFox; tK6=F63e
jFI`CA6P
s;[WN.
import java.io.*; L9!\\U
import java.net.*; DIkf#}
fW=eB'Sl
7IrH(~Fo
public class FileSplitterFetch extends Thread { d9l2mJzW
bu=RU
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String sURL; //File URL `1lGAKv
long nStartPos; //File Snippet Start Position uu/2C \n}
long nEndPos; //File Snippet End Position Ve xxdg
int nThreadID; //Thread's ID (yB]$
boolean bDownOver = false; //Downing is over Qn;,OBk
boolean bStop = false; //Stop identical |:L}/onK
FileAccessI fileAccessI = null; //File Access interface <2N=cH'
0="wxB
{??bJRT
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^3QJv{)Q
{ {9cjitl
this.sURL = sURL; zT>BC}~.b
this.nStartPos = nStart; lx> ."rW
this.nEndPos = nEnd; lnK#q.]
nThreadID = id; .kB!',v\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /?V-
} Q9&H/]"v
'*<I<? z;
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public void run() nW oh(a
{ O0eM*~zI
while(nStartPos < nEndPos && !bStop) }:!X@C~
{ drbim8!q~
eAjsMED
/E:BEm!
try{ fT YlIT9
URL url = new URL(sURL); bas1(/|S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hUEA)c
httpConnection.setRequestProperty("User-Agent","NetFox"); yA';~V\V{>
String sProperty = "bytes="+nStartPos+"-"; wR"17z7[]
httpConnection.setRequestProperty("RANGE",sProperty); |<MSV KW
Utility.log(sProperty); F!-%v5.y
Q07&7SH_
FB %-$
InputStream input = httpConnection.getInputStream(); FbXur-et^
//logResponseHead(httpConnection); TYCjVxfu$
3u< ntx ><
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byte[] b = new byte[1024]; bHQ) :W
int nRead; Ko|gH]B'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pm[+xM9PB
{ oqzWL~
nStartPos += fileAccessI.write(b,0,nRead); bV+2U
//if(nThreadID == 1) aj<r=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e%IbME]x
} jsP+,brO
cM]ZYi
m|v$F,Lv
Utility.log("Thread " + nThreadID + " is over!"); ZKM@U?PK
bDownOver = true; #$}A$sm
//nPos = fileAccessI.write (b,0,nRead); 5=8t<v1Bn
} ,hm&]
catch(Exception e){e.printStackTrace ();} R\]C;@J<
} lbC,*U^
} ~.tYYX<
oN`khS]_v0
qqys`.
//打印回应的头信息 \s!x;nw[
public void logResponseHead(HttpURLConnection con) ? 51i0~O=
{ "]OROJGa
for(int i=1;;i++) -aV(6i*n
{ `Jh<8~1
String header=con.getHeaderFieldKey(i); )JJF}m=
if(header!=null) "8~PfLJ+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,H1K sN
Utility.log(header+" : "+con.getHeaderField(header)); u'T-}95 V
else n~0MhE0H
break; =ADOf_n}
} @uanej0q7
} |*Oi:)qt
p7HLSB2Rp
U+C^"[B
public void splitterStop() M27H{}v
{ u4bVp+
bStop = true; qh6rMqq
} }0iHf'~DH*
Xz9[0;Q
>?6HUUQ
} JpxQS~VX
GRaU]Z]ck
g's!\kr
/* ~Yc!~Rz
**FileAccess.java D4uAwmc
*//文件访问(定位，写) V^rL
package NetFox; 5=%KK3
import java.io.*; iio-RT?!
kt=&mq/B
"h|kf% W
public class FileAccessI implements Serializable{ {s@ 0<!
]2 $T 6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X4Pm&ol
RandomAccessFile oSavedFile; lxr;AJ(
long nPos; j(k}NWPH
b*/Mco 9O
#=;vg
public FileAccessI() throws IOException /Gn0|]KI
{ X{<taD2~
this("",0); ]Qa|9G,b
} E0yx @Vx
i0J`{PbI
%wI)uJ2
public FileAccessI(String sName,long nPos) throws IOException _pDfPLlY&
{ dCo3VF"u
oSavedFile = new RandomAccessFile(sName,"rw"); yH>C7M7t
this.nPos = nPos; wNn=JzP
oSavedFile.seek(nPos); pf%;*
} F^`+.G\
Nwe-7/Q
?%Ww3cU+J
public synchronized int write(byte[] b,int nStart,int nLen) e8#83|h
{ <XtE|LG
int n = -1; /+8VW;4|I
try{ KY%{'"'u
oSavedFile.write(b,nStart,nLen); s`0IyQXVU
n = nLen; W/}_y8q
} +\)Y,@cw
catch(IOException e) vU]n0)<KB
{ @LSh=o+
e.printStackTrace (); u[oV Jvc
} O.-n&U9
_N)&<'lB<
es~1@Jb
return n; p\9}}t7n
} Yl:[b{Py
{cb<9Fii
;r&Z?B$
} s9OW.i]zX
O:GAS [O`
os&FrtDg
/* vxLr034
**SiteInfoBean.java [HUK 9hG
*/ %u_dxpx
package NetFox; kytHOn#
C'R6mz%Q?
K]G(u"'
public class SiteInfoBean { ezCJq`b
\=]`X2Ld
~8"oH5
private String sSiteURL; //Site's URL #NYHwO<0-
private String sFilePath; //Saved File's Path ';c 6
private String sFileName; //Saved File's Name ?Zsh\^k.g
private int nSplitter; //Count of Splited Downloading File ^8J`*R8CL
6EO@Xf7,
VX>j2Z'
public SiteInfoBean() 5Pxx)F9]
{//nSplitter的缺省值为5 .Eb]}8/}E
//default value of nSplitter is 5 ~PpDrJ; Va
this("","","",5); <VutwtA
} v Y0ESc{
:FfEjNil
f}p`<z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &/ED.K
{ RqP_^tB
sSiteURL= sURL; RyG6_G}
sFilePath = sPath; B]:|;d
sFileName = sName; 0NKgtH~+
this.nSplitter = nSpiltter; sR[!6[AA
)0ydSz`B
*Uj;a.
} k0#s{<I]E
wfpl]d!
~zG)<S"q
public String getSSiteURL() f1+
{ VB#&`]rdo
return sSiteURL; R! On
} EP>Lh7E9n
('UTjV
0t}v@-abU
public void setSSiteURL(String value) t[|t0y8
{ <hiv8/)?
sSiteURL = value; BRskxyL&,
} "bF52lLu
QKB+mjMH#x
K/ &`
public String getSFilePath() 9==4T$nM[
{ LjTSu9I>
return sFilePath; .`5|NUhN
} UB~-$\.
9__B!vw:
79@CO6
public void setSFilePath(String value) hf0(!C*
{ jC>#`gD
sFilePath = value; D GcpYA.7'
} qtozMa
T!B\ixt6
kWVk^,
public String getSFileName() iLNUydiS
{ [ }Tb2|
return sFileName; r@qLG"[\c
} 9_iwikD
wWfj#IB;R
vmrs(k "d#
public void setSFileName(String value) 6$=>ckP
{ 1'Q6l
sFileName = value; }2"W0ZdWD
} 2,`X@N`\
$p4e8j[EJ
EPH" 5$8
public int getNSplitter() .ml\z5
{ GD]epr%V
return nSplitter; adIrrK
} ;nQ=! .#Q
zGyRzxFN
~jzLw@"~$^
public void setNSplitter(int nCount) @48!e-W
{ \G>C{v;
nSplitter = nCount; 1/w8'Kf'u
} Qkx*T9W
} IF|;;*Z8
? ,s'UqR
Nc{&AV8Y_v
/* $w{d4")
**Utility.java Q2r[^Z
*/ x[0hY0 ?[M
package NetFox; `4'=&c9
P(b[|QF
y$]<m+1
public class Utility { JZ`h+fAt
!Md6Lh%-w
}EkL[H!
public Utility() J( XDwt
{ FI[BZZW
iJ^}{-
*nJ,|T
} 5;" $X 1{
?2~fvMWu
//线程睡眠 {G x=QNd
public static void sleep(int nSecond) {TpbUj0
{ gFHBIN;u
try{ !(?7V
Thread.sleep(nSecond); =dA]nM
} ~nmFZ]y
catch(Exception e) xcWR#z{z
{ 2{~`q
e.printStackTrace (); ~&T U
} iD|~$<9o
} nng|m
}lX$KuD
//日志 OHBCanZZ,
public static void log(String sMsg) [niFJIsc
{ R3_OCM_*
System.err.println(sMsg); [.xY>\e
} qm><}N7f
s) U1U6O
3\j`g
public static void log(int sMsg) 4Xa]yA =
{ :FS5BT$=
System.err.println(sMsg); b7\>=
} fb`x1Q
} m=@xZw<
"Ux(nt
i@?|vu
/* n5UUoBv
**TestMethod.java /fb}]e]N
*/ mJ<`/p?:
package NetFox; f<wYJGI
-+1O*L!
)SJM:E
public class TestMethod { 3 5.&!4}
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1]=X
public TestMethod() lPxhqF5pP
{ ///xx/weblogic60b2_win.exe T})q/oUqK
try{ J~WT;s
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8=L"rekV_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `9[n5-t
SiteFileFetch fileFetch = new SiteFileFetch(bean); B3&C&o.h
fileFetch.start(); ddKP3}
} BT8)t.+pv
catch(Exception e){e.printStackTrace ();} :s_.K'4?a
: H;S"D
iE"]S )
} |}:}14ty
&nr{-][
^P~,bO&H.Z
public static void main(String[] args) _|12BVq
{ 8e>B>'nH
new TestMethod(); tkHmH/'7
} oX:&;KA
} ZYWGP:Y
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