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)); )M0(vog
} 6k;5T
for(int i=0;i<nEndPos.length-1;i++) "|Q.{(|kO1
{ E<+ G5j
nEndPos = nStartPos[i+1]; ~{lb`M^]h
} :5/Ue,~ag
nEndPos[nEndPos.length-1] = nFileLength; EF:ec9 .
} BkB_?^Nv8
} M}[Q2v\
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6agG*x
//启动子线程 8a8a:d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 36OQHv;&
for(int i=0;i<nStartPos.length;i++) SeXgBbGAne
{ xK_UkB-$i
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9k71h`5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `{{6vb^g
nStartPos,nEndPos,i); UZs '[pm)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jkj7ty.J
fileSplitterFetch.start(); kl:/PM^
} Ywhhs }f
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qX\85dPn@}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); VC/n}7p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]*| hd/j
nEndPos = " + nFileLength); #sCR}
// fileSplitterFetch[nPos.length-1].start(); wnd #J `
m-uXQS^@G
Vc9Bg2f5
//等待子线程结束 ":+d7xR?o
//int count = 0; </_QldL_
//是否结束while循环 ,H6P%
boolean breakWhile = false; zNo,PERG
@Ik5BT
J&\Q3_vro9
while(!bStop) \wz^Z{U
{ IQ\!wWKmY
write_nPos(); ^}$t(t
Utility.sleep(500); >4wigc
breakWhile = true; i/_rz.c~3
f91]0B`C
>mA]2gV<a
for(int i=0;i<nStartPos.length;i++) @xo8"kl
{ 'L O3[G{
if(!fileSplitterFetch.bDownOver) -S]ercar
{ A nl1+
breakWhile = false; I(VqtC:K.
break; axC{azo|
} hJ8&OCR }
} }\<=B%{
if(breakWhile) *3Lo[GE>
break; ;q-c[TZC
-5og)ZGVUA
^jL)<y4`
//count++; ]g$ky.;
//if(count>4) 46T(1_Xt~
// siteStop(); ~`e!$=
} ' u<IS/w
+$ djX=3
6,LE_ -G5
System.err.println("文件下载结束！"); BKTTta1mY
} xS@jV6E~
catch(Exception e){e.printStackTrace ();} (^B1Kt!<
} M/W9"N[ta
*sp")h#Z
wE1GyN
//获得文件长度 />Zfx.Aj6
public long getFileSize() &#C&0f8PnD
{ U*K4qJ6U
int nFileLength = -1; )( 3)^/Xz
try{ t9<BQg
URL url = new URL(siteInfoBean.getSSiteURL()); 2d|^$$#`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0c"9C_7^g
httpConnection.setRequestProperty("User-Agent","NetFox"); 2UYtEJ(?`{
5w>TCx
V$DB4YM1k
int responseCode=httpConnection.getResponseCode(); AUF[hzA
if(responseCode>=400) do^=Oq07$
{ c[M4l
processErrorCode(responseCode); th*!EFA^o
return -2; //-2 represent access is error vh2/d.MO
} Yqh-U%"'
ES,JdImZ|
kPy7e~
String sHeader; !Usmm8!K
1^NC=IS9z
6%t6u3
for(int i=1;;i++) [YlRz
{ $H@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oAN,_1v)
//Utility.log(in.readLine()); p Cx_[#DrP
sHeader=httpConnection.getHeaderFieldKey(i); EK>x\]O%T
if(sHeader!=null) >N! Xey
{ E5S(1Z}]p{
if(sHeader.equals("Content-Length")) gF9GU5T:
{ @+~URIG)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'U&]KSzxv
break; `@\FpV[|P
} ?-&k?I
} !4^Lv{1QZ
else Ye|gW=FUR
break; ql.[Uq
} u7J:ipyiq2
} M3KK^YRN
catch(IOException e){e.printStackTrace ();} -+qg
catch(Exception e){e.printStackTrace ();} '$yy
r4FSQ$[9w
vbd ;Je"
Utility.log(nFileLength); \0}bOHqEH
3k6Dbz
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return nFileLength; (`Y;U(n
} .I{u[ "
K ..Pn17t
l8M}82_
//保存下载信息（文件指针位置） dcemF
private void write_nPos() 7{"F%`7L
{ Z{ YuX
try{ K7x;/O
output = new DataOutputStream(new FileOutputStream(tmpFile)); Pj56,qd>s
output.writeInt(nStartPos.length); - ]We|{
for(int i=0;i<nStartPos.length;i++) }n^}%GB
{ _,F\%}
// output.writeLong(nPos); MftaT5
output.writeLong(fileSplitterFetch.nStartPos); ZrP 8/>
output.writeLong(fileSplitterFetch.nEndPos); B[&l<*O-y
} yIpgZ0:h
output.close(); #Sy~t{4
} i%f C`@
catch(IOException e){e.printStackTrace ();} ,,EG"Um6
catch(Exception e){e.printStackTrace ();} U;ujN8
} !f!YMpN
!:vQg+S
b+AxTe("
//读取保存的下载信息（文件指针位置） gi:M=
private void read_nPos() 5B1,,8P
{ CucW84H`J
try{ @!x7jPr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [=-,i#4
int nCount = input.readInt(); o2YHT \P n
nStartPos = new long[nCount]; kotKKs
nEndPos = new long[nCount]; <#Fex'4
for(int i=0;i<nStartPos.length;i++) jtpk5 fJB
{ H`3w=T+I
nStartPos = input.readLong(); <VN< ~sz
nEndPos = input.readLong(); DB jUHirK
} Q[`2?j?
input.close(); .Xxxz Wyk
} "AWk jdj
catch(IOException e){e.printStackTrace ();} &8%^o9sH
catch(Exception e){e.printStackTrace ();} Iw$T'I+4W
} w3fD6$
JqN$B\J,
"$"<AKCwS
private void processErrorCode(int nErrorCode) rTC|8e
{ P4MP`A
System.err.println("Error Code : " + nErrorCode); 6QPbmO]z
} w3>G3=b
H?ue!5R#L
(a,`Y.
//停止文件下载 0icB2Jm:D}
public void siteStop() JO87rG
{ ]/R>nT
bStop = true; ]YDqmIW
for(int i=0;i<nStartPos.length;i++) "tK3h3/Xv
fileSplitterFetch.splitterStop(); La^Zr,T!
f|!@H><
{qry2ZT5
} Jju?v2y`
} 5(\[Gke
//负责部分文件的抓取 lm'.G99{
**FileSplitterFetch.java ?K.!^G
*/ 1Ji"z>H*
package NetFox; at3YL[,[Z
e [F33%
Uzn
import java.io.*; eLyIQoW
import java.net.*; wDh&S{N
w6B`_Z'f
!wrAD"l*@
public class FileSplitterFetch extends Thread { 9I|Q`j?p`
{#{nU NW
% e70*;
String sURL; //File URL giN(wPgYP
long nStartPos; //File Snippet Start Position LR17ilaa'
long nEndPos; //File Snippet End Position +hWeN&A
int nThreadID; //Thread's ID xJvalb
boolean bDownOver = false; //Downing is over mL,{ZL ^
boolean bStop = false; //Stop identical l4^8$@;s
FileAccessI fileAccessI = null; //File Access interface ,6U=F#z
hn/SS
Qbj:^{`>(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zWdz9;=_
{ m]\d9%-AT&
this.sURL = sURL; OL&VisJ{75
this.nStartPos = nStart; NL ceBok
this.nEndPos = nEnd; G~4|]^`g
nThreadID = id; ht5:kt`F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7nPm{=BG
} wi:d!,P`e
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AWmJm)
public void run() %__.-;)o
{ l)0yv2[h
while(nStartPos < nEndPos && !bStop) .aIFm5N3?
{ T~N877
D <Fl7QAb
o\yqf:V8
try{ kZ 9n@($B
URL url = new URL(sURL); SR\$fmo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fg^zz*e
httpConnection.setRequestProperty("User-Agent","NetFox"); [ **F
String sProperty = "bytes="+nStartPos+"-"; %{P." ki
httpConnection.setRequestProperty("RANGE",sProperty); -| t|w:&
Utility.log(sProperty); v-Uz,3
bNz2Uo!0K
_ID =]NJ_
InputStream input = httpConnection.getInputStream(); /^Lo@672
//logResponseHead(httpConnection); E!>l@ ki
rg+3pX\{
]h&?^L<.
byte[] b = new byte[1024]; z:W1(/W~
int nRead; ~leLQsZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :&D$Q 4
{ Z@:R'u2Lk
nStartPos += fileAccessI.write(b,0,nRead); }pPt- k
//if(nThreadID == 1) }Qvoms<k
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wsCT9&p
} ok9G9|HA
%6<2~
:20k6)
Utility.log("Thread " + nThreadID + " is over!"); A}n5dg0u
bDownOver = true; AwGDy +
//nPos = fileAccessI.write (b,0,nRead); j: B,K.:
} 2HvzMo-4
catch(Exception e){e.printStackTrace ();} OBp/:]
} %O&C\{J
} 27jZ~Bp$
0 :1ldU 4
12%4>2}~>
//打印回应的头信息 - e"XEot~
public void logResponseHead(HttpURLConnection con) 1HNX6
{ m-!z(vcn
for(int i=1;;i++) |teDe6\m
{ k+&1?]
String header=con.getHeaderFieldKey(i); vR\[IV?
if(header!=null) _b 8XF&O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z$a4@W9o
Utility.log(header+" : "+con.getHeaderField(header)); z15QFVm
else O0<GFL$)&
break; ZZl4|
} !J@pox-t
} `<l|XPv
,TxZ:f`"
uv dx>5]
public void splitterStop() A&fh0E (t
{ c)o[3o7
bStop = true; ]^\+B4
} $JXQn
mJ5LRpXN
h?:Y\DlU'
} Y_Lsmq2!
7QkAr
,s1n!@9
/* ui6B
**FileAccess.java r\66]u[
*//文件访问(定位，写) ?|9$o/Q}
package NetFox; /L"&'~
import java.io.*; ;42D+q=s
QWGFXy,=1
"ae55ft//
public class FileAccessI implements Serializable{ yo0?QRT
_j2h3lCT
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CSooJ1Ep~'
RandomAccessFile oSavedFile; Iq[,)$
long nPos; $/(H%f&
a?!Joi[
NeyGIEP
public FileAccessI() throws IOException /`Lki>"
{ W\<5'9LNb
this("",0); HCifO
} ,Pd2ZfZ
[%8+Fa~Wa
"]`QQT-{0
public FileAccessI(String sName,long nPos) throws IOException DDhc^(
{ |KC3^
oSavedFile = new RandomAccessFile(sName,"rw"); Kn9,N@bU_
this.nPos = nPos; CQ3{'"b
oSavedFile.seek(nPos); w65 $ R
} _?2xIo
thDE 1h
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public synchronized int write(byte[] b,int nStart,int nLen) Q$9`QY*6"p
{ ?Xo9,4V1
int n = -1; X|wXTecg*|
try{ #Y*AGxk
oSavedFile.write(b,nStart,nLen); F'#e]/V1
n = nLen; .9g\WH#qD|
} c~|/,FZU'
catch(IOException e) hK$-R1O
{ y6?Q5x9M
e.printStackTrace (); HF\L`dJX?
} tIC_/ 6
q& Vt*
Yazpfw 7'd
return n; 6C/D&+4
} Zy7@"C
d*,|?Ar*b
VuZmX1x)N
} Ck.GN<#-^P
tZXtt=M w
MOmp{@
/* aTs_5q
**SiteInfoBean.java ^HL#)fK2I
*/ XfsCu>
package NetFox; }wkBa]
5>w>J
1^zF/$%
public class SiteInfoBean { gi@+27;
Z9aDE@A
>8tE`2[i*
private String sSiteURL; //Site's URL &:jE+l
private String sFilePath; //Saved File's Path nw5#/5xw
private String sFileName; //Saved File's Name D0k7)\puQ
private int nSplitter; //Count of Splited Downloading File D1O7S]j
Vq'&t<K#
m9xu$z|e
public SiteInfoBean() }}(~'
{//nSplitter的缺省值为5 \^-3)*r
//default value of nSplitter is 5 ?\#4`9
this("","","",5); 4'rk3nT8
} 6^: l
>uJrq""+
c*1x*'j.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?I/,r2ODLh
{ c@q>5fR/c
sSiteURL= sURL; l2`8]Qr
sFilePath = sPath; T)Nis~
sFileName = sName; >v<}$v6D~
this.nSplitter = nSpiltter; d=4MqX r
d$2{_6
"|Q&
} ;LrKXp
kkOYC?zE?
Mc6Cte]3|
public String getSSiteURL() nC&rQQFF
{ @xkM|N?
return sSiteURL; _mkI;<d]$T
} 3P\I;xM
b]g.>$[nX
O:BP35z_F
public void setSSiteURL(String value) [7s5Vt|
{ ;Ok11wOw
sSiteURL = value; ?<LG(WY
} n'h )(^
w\2[dd
r2H'r ,N
public String getSFilePath() ;5%&q6&a
{ UZAWh R
return sFilePath; Dk"M8_-_
} 1[Mr2@
s{: Mu~v
g*tLqV
public void setSFilePath(String value) _fyw
{ 25~$qY_
sFilePath = value; sw@2 ?+
} B6pz1P?e}
Sl_zO?/PF
B]qh22Yib
public String getSFileName() ^LcI6h
{ YI|Gpq
return sFileName; ?\pE#~m
} Qom@-A
/1>
D&^:hs@
public void setSFileName(String value) EqmJXDm
{ BxT~1SBFq
sFileName = value; Sd\@Q% }o\
} 88*RlxU
d!LV@</
<V8i>LBlz
public int getNSplitter() 7S7!
{ Y}#^n7*w~
return nSplitter; f:Ja
} 'q^Gg;c>+
D8#q.OR]
&Egn`QU
public void setNSplitter(int nCount) ?^!dLW
{ 1!C,pXU#:
nSplitter = nCount; Kk(ucO
} cU6#^PFu
} E0hp%:
s*X\%!l9
&B85;
/* KN`z68c4L
**Utility.java Q+Fw =Xw
*/ ppD~xg]
package NetFox; A X#!9-m3
U`Ag|R
A-u5
public class Utility { =iQm_g
0EB'!
X]*/]Xx
public Utility() .0-m=3mp2
{ ykeUS zz2
Y_B 4s-
iLgt_@g
} :&-}S>pC
:Ir:OD#o
//线程睡眠 .:raeDrd
public static void sleep(int nSecond) T??aVe]c
{ *;d)'7<
try{ <`*P/V
Thread.sleep(nSecond); #]N9/Hij#g
} ^k(eRs;K
catch(Exception e) kC5,yj
{ n6Zx0ad?
e.printStackTrace (); o5@ jMU;
} /#=J`*m_
} A m1W<`
u_"h/)C'H
//日志 -YyH"f
public static void log(String sMsg) r97[!y1gt
{ 3ky+qoe
System.err.println(sMsg); l1qwT0*6>
} B3t>M) 9
1Qu,]i`
15:@pq\
public static void log(int sMsg) TjK5UML
{ 90ag!
System.err.println(sMsg); jq)|7_N
} P0(~~z&%[
} PZR%8 m}]u
@R&D["!
|Z^g\l.j{
/* ` W>B8
**TestMethod.java E|;5Z*
*/ &RrQ()<as
package NetFox; +|<&#b0Xd
aF"Z!HD
Hc%\9{zH
public class TestMethod { =M#?*e
-b}S3<15@
X4G55]D$>
public TestMethod() %Nl(Y@dD*
{ ///xx/weblogic60b2_win.exe 7YjucPH#
try{ vaOL6=[#:g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d)ZSzq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `UK+[`E
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ux T[
fileFetch.start(); MEnHC'nI
} :+Ax3
catch(Exception e){e.printStackTrace ();} gtGKV
aQ:f"0fL
)o</gt)
} z 2VCK@0
32LB*zc
s)8M? |[`I
public static void main(String[] args) %,cFX[D/)
{ A<5`[<x$
new TestMethod(); yaLW(@
} xBfe8lor
} LC\:xia{X
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