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)); YoJN.],gf
} RV-7y^[]^
for(int i=0;i<nEndPos.length-1;i++) dF"Sz4DY#
{ ]*?qaIdqu
nEndPos = nStartPos[i+1]; /_v@YB!0
} 1qtu,yIf
nEndPos[nEndPos.length-1] = nFileLength; M(xd:Fa?
} *:wu{3g}M`
} 7i`8 c =.
7Q2"]f,$CQ
4Y[tx]<
//启动子线程 s#>Bwn&b)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |,|b~>
for(int i=0;i<nStartPos.length;i++) ULj'DzlfH
{ ,*Jm\u
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !>TH#sU$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1t6VS3
nStartPos,nEndPos,i); 5#~u U
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Mz_*`lRN
fileSplitterFetch.start(); 4gzrxV
} '7 SFa]tH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pbt/i+!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lOYzo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", jw]~g+x#$
nEndPos = " + nFileLength); A70x+mjy^T
// fileSplitterFetch[nPos.length-1].start(); *H8(G%a!^
8SR~{
D<78Tm x
//等待子线程结束 8K=sx@l
//int count = 0; }j;*7x8(
//是否结束while循环 v@(Y:\>
boolean breakWhile = false; .-Yhpw>f
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d ]R&mp|'
while(!bStop) W{B)c?G]
{ DEM;)-D
write_nPos(); #-r,;
Utility.sleep(500); U=QfInB
breakWhile = true; F l@%?
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?VaWOwWI
for(int i=0;i<nStartPos.length;i++) 9Kf# jZ
{ 9M8n
if(!fileSplitterFetch.bDownOver) JL.noV3q$
{ (r78AZ
breakWhile = false; LX5, _`B
break; '@t}8J
} _8]hn[
} WCJ$S\#
if(breakWhile) Gpv9~&
break; 9=D09@A%e
9[31EiT
F-0|&0
//count++; zI1-l9 o
//if(count>4) `0'Bg2'
// siteStop(); RHe'L36W
} MOp06
x"7`,W
<e)5$Aj
System.err.println("文件下载结束！"); b8o}bm{s
} >AFX}N#
catch(Exception e){e.printStackTrace ();} l.gt+e
} *?dw`j_b >
%VZQX_
1j4(/A
//获得文件长度 ~m@v ~=
public long getFileSize() H! IL5@@K
{ G3r9@2OC
int nFileLength = -1; >d1gVBhk
try{ hqr V {c
URL url = new URL(siteInfoBean.getSSiteURL()); DSb/+8KT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YhpNeP{A
httpConnection.setRequestProperty("User-Agent","NetFox"); rwYlg:
X%1j-;Wr@
AiMD"7 )c
int responseCode=httpConnection.getResponseCode(); Dl/Jlsd@
if(responseCode>=400) kWkAfzf4a
{ KNH.4A ,
processErrorCode(responseCode); >'\cNM~nf
return -2; //-2 represent access is error n+Bh-aV
} L!fiW`>0G
~QVN^8WPg
TttD}`\.
String sHeader; 1lAx"VL
gtizgUS7
8`edskWrU
for(int i=1;;i++) 4O~E4" ]
{ RfM uWo:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `/+%mKlC|[
//Utility.log(in.readLine()); ` #!~+
sHeader=httpConnection.getHeaderFieldKey(i); Y%1J[W
if(sHeader!=null) zQ[g*
{ _!m_s5{
if(sHeader.equals("Content-Length")) +s(JutC
{ ?hW?w$C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WGG Va
break; >%vw(pt
} ]yzqBbV
} &PfCY{_
else OIT9.c0h
break; ve#*qz Y
} mQVc ZV
} JjH#,@'.
catch(IOException e){e.printStackTrace ();} y(I_ 6+B^
catch(Exception e){e.printStackTrace ();} t6zc$0-j"
0)c9X[sG
'eKvt5&@
Utility.log(nFileLength); !>%U8A
jQrj3b.NC3
UIpW#t
return nFileLength; 32DSZ0
} Y5J}*`[Mr
`vkNp8|
T2;%@Ghc
//保存下载信息（文件指针位置） c^N'g!on
private void write_nPos() 37#|X*L
{ HkGA$
try{ $6&P 69<
output = new DataOutputStream(new FileOutputStream(tmpFile)); \t'v-x>2y5
output.writeInt(nStartPos.length); Y Mes314"
for(int i=0;i<nStartPos.length;i++) Cfizh@<
{ 6mFH>T*jzH
// output.writeLong(nPos); aY/msplC
output.writeLong(fileSplitterFetch.nStartPos); tb%u<jY
output.writeLong(fileSplitterFetch.nEndPos); y;0k |C
} A7{l60(5
output.close(); r*-e~
} ^H0`UKE
catch(IOException e){e.printStackTrace ();} lq4vX^S
catch(Exception e){e.printStackTrace ();} 9t`Z_HwdCb
} 5&&6e`
sd (I@ &y
-jBk
//读取保存的下载信息（文件指针位置） P)7_RE*gY
private void read_nPos() .zm'E<
{ Je|D]w
try{ 3f 1@<7*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f87>ul!*
int nCount = input.readInt(); "8pfLI
nStartPos = new long[nCount]; c1v,5c6d j
nEndPos = new long[nCount]; FTB@70
for(int i=0;i<nStartPos.length;i++) vV2px
{ .Yl*kG6r
nStartPos = input.readLong(); x]({Po4
nEndPos = input.readLong(); ya+eGD@N':
} \u|8MEB
input.close(); 9Y9pKTU
} 2r+@s g
catch(IOException e){e.printStackTrace ();} D,aJ`PK~
catch(Exception e){e.printStackTrace ();} wH:'5+u:6
} QK+s}ny
Ov vM)?^#
n&?]GyQ
private void processErrorCode(int nErrorCode) X%S9H^9
{ .x$!Rc}
System.err.println("Error Code : " + nErrorCode); >E;&SX
} {H$F!}a
jGB2`^&d
7e,EI9?.
//停止文件下载 .O\z:GrSZz
public void siteStop() <h_lc}o/
{ vXUrS+~x
bStop = true; X#s:C=q1
for(int i=0;i<nStartPos.length;i++) yFt'<{z[nL
fileSplitterFetch.splitterStop(); m6qmZ2<
dXKv"*7l
oR.KtS$uh
} G0sg\]
} TQx''$j\
//负责部分文件的抓取 F,^<
**FileSplitterFetch.java oa:GGW4Q
*/ 9v(&3,)a
package NetFox; e+"rL]
xg~ Baun
\ H#zRSbZ
import java.io.*; >w:px$g4
import java.net.*; Sd]`I)
s[:e '#^
6&% c
public class FileSplitterFetch extends Thread { U8?%Dq%i
Or&TGwo I
?YY'-\h?
String sURL; //File URL XUUl*5^
long nStartPos; //File Snippet Start Position A_: Bz:
long nEndPos; //File Snippet End Position '?+q3lps
int nThreadID; //Thread's ID ~4th;#'
boolean bDownOver = false; //Downing is over pCSR^ua>
boolean bStop = false; //Stop identical ZHxdrX)
FileAccessI fileAccessI = null; //File Access interface /nEh,<Y)
#uNQ+US0
"}PaMR]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IfoeHAWX
{ =@b/Gl
this.sURL = sURL; vJkY
this.nStartPos = nStart; hV_eb6aj}P
this.nEndPos = nEnd; %&bO+$H3
nThreadID = id; ![os5H.b#q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *]%{ttR~
} #5)E4"m
sHO6y0P
b,YTw
public void run() ;5 cg<~t
{ UJ1Ui'a(!!
while(nStartPos < nEndPos && !bStop) +)Tt\Q%7
{ #KZ6S9>@
FbQ"ZTN\;Y
^G{3x
try{ *M;!{)m?
URL url = new URL(sURL); q#Az\B:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F*hOa|7/
httpConnection.setRequestProperty("User-Agent","NetFox"); 1]#qxjZ~
String sProperty = "bytes="+nStartPos+"-"; -Cv:lJj
httpConnection.setRequestProperty("RANGE",sProperty); Cul^b_UmP#
Utility.log(sProperty); 9mkt.>$
n= yT%V.l
<jXXj[M2
InputStream input = httpConnection.getInputStream(); %"V Y)
//logResponseHead(httpConnection); LhC%`w
hZ!N8nWwNR
{E!ie{~
byte[] b = new byte[1024]; 2MmqGB}YcW
int nRead; ; k{w@L.@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0 } uEM_a
{ :P<} bGN
nStartPos += fileAccessI.write(b,0,nRead); j K?GB
//if(nThreadID == 1) x3O$eKy\|5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !vHUe*1a{
} TO.?h!
]N!382
'`=z52
Utility.log("Thread " + nThreadID + " is over!"); Qy`{y?T2
bDownOver = true; R"#DR^.;
//nPos = fileAccessI.write (b,0,nRead); ae( o:G
} PpX=~Of~
catch(Exception e){e.printStackTrace ();} vs;T}'O
} V|xKvH
} >Du5B&41
o%X@Bz
hK*:pf
//打印回应的头信息 ) D:M_T2
public void logResponseHead(HttpURLConnection con) =7pLU+ u
{ 2i`N26On
for(int i=1;;i++) <<!XWV*m
{ lR_ 4iyqb
String header=con.getHeaderFieldKey(i); 3\WLm4
if(header!=null) 9{_D"h}}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P3C|DO4
Utility.log(header+" : "+con.getHeaderField(header)); `G> 6
else {^ 1s
break; /Ps}IW
} is?H1V~8`$
} VXlTA>a }
pH5"g"e1
A$vCm
public void splitterStop() jrT5Rw_}q
{ I@~hz%'
bStop = true; q@1!v
} 5-lcz)DO
9^l_\:4
5#/"0:2
} ?<VahDBS+A
8"l9W=
"mr;|$Y
/* z 3)pvX5
**FileAccess.java e#]=-^
*//文件访问(定位，写) u!`oKe;
package NetFox; .6S]\dp7~
import java.io.*; ]>-#T
e{@TR x
]Ija,C!#
public class FileAccessI implements Serializable{ q5J6d+
NMb`d0;(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Z[:fqvXQ
RandomAccessFile oSavedFile; ?'uxYeX6
long nPos; r2H_)Oi
)TV4OT#
K| #%u2C
public FileAccessI() throws IOException R4=n">>Q
{ u1d{|fF
this("",0); u(V4KUk
} is_`UDaB
O.4ty)*
U{n< n8
public FileAccessI(String sName,long nPos) throws IOException tj@IrwC^e"
{ ~3 4Ly
oSavedFile = new RandomAccessFile(sName,"rw"); +FiM?,G
this.nPos = nPos; _KVge)j
oSavedFile.seek(nPos); @A6P[r
} 6+HpN"?e
JJlwzH
J8w#J
public synchronized int write(byte[] b,int nStart,int nLen) y1P KoN|K
{ .r!:` 6
int n = -1; Fa78yY+6
try{ FaO1?.
oSavedFile.write(b,nStart,nLen); j<w";I&Diz
n = nLen; sLh9=Kh`
} En%PIkxeR
catch(IOException e) )HWf`;VQ
{ ;KqH]h)
e.printStackTrace (); bQc-ryC+.
} %|md0
#xZ7%
aV3:wp]Gn
return n; j]i:~9xKW
} b#cXn4<3D
h;105$E1
tpp. 9
} z$OKn#%T
.T0w2Dv/
@MMk=/WDw
/* Oi#F
**SiteInfoBean.java Om`VQ?
*/ Y(QLlJ*)/
package NetFox; &t1?=F,]
?h)Z ;,}
|#^##^cF/
public class SiteInfoBean { k fS44NV
:[f2iZ"
qzq_3^66
private String sSiteURL; //Site's URL (bnyT?p%
private String sFilePath; //Saved File's Path E _d^&{j
private String sFileName; //Saved File's Name Ul#||B .c{
private int nSplitter; //Count of Splited Downloading File mZLrU<)Y
QTX5F5w
s"5f5Cn/Wh
public SiteInfoBean() y7J2:/@[x
{//nSplitter的缺省值为5 \]pRu"
//default value of nSplitter is 5 8nn%wps
this("","","",5); B;f\H,/59
} p&'oJy.P
RzG7Xr=t
Q; DN*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ZZ/F}9!=
{ Uz(Sv:G
sSiteURL= sURL; M(>"e*Pi
sFilePath = sPath; {=n-S2%
sFileName = sName; := OdjfhY
this.nSplitter = nSpiltter; t# cm|
nlv8HC
;Y<Hi\2oy
} Th&-n%r9K
-P"9KnsO
EXt?xiha?
public String getSSiteURL() 78'HE(*
{ aKi&2>c5>
return sSiteURL; h>>KH*dQ
} r)S tp`p
$Pw@EC]
t[>y=89
public void setSSiteURL(String value) ' fXBWi6
{ |l5ol@2*
sSiteURL = value; 3/+r*lv>X
} ')!+>b(P
70s.
)3h%2C1uM
public String getSFilePath() [QC<u1/"K
{ A6D.bJ)
return sFilePath; Z/#l~.o[
} 01bBZWX
U;%I" p`Z/
HoA[UT
public void setSFilePath(String value) |^z?(?w
{ QuEfV?)_4
sFilePath = value; VKzY6
} SRL`!
s{IXth6
jkz.qo-%
public String getSFileName() r?^[o
{ `$V7AqX(
return sFileName; BK,h$z7#6
} (?luV#{5
v.eNWp
RPH]@
public void setSFileName(String value) bwHl}3
{ -Fi{[%&u
sFileName = value; JPeZZ13sS
} vn5X]U"
"S#}iYp
AGxtmBB;
public int getNSplitter() N =k}"2_=
{ T(< [k:`
return nSplitter; y,I?3p|S
} ;W ZA
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>MXE)=
public void setNSplitter(int nCount) irqNnnMGEa
{ x6=Yt{
nSplitter = nCount; 'A#`,^]uLF
} [A@K)A$f
} v=-8} S
gY)NPi}!`
YX||\
/* v };r
**Utility.java *k&yD3br-V
*/ f7y a0%N
package NetFox; K YSyz)M}
]QB<N|ps
I/whpOg
public class Utility { B,`B!rU
P)hZFX
*rs@6BSj
public Utility() 6fP"I_c
{ $UgQ1Qc
%RlG~a
Q> Lh.U,{
} fc}G6P;3{
zli@XZ#
//线程睡眠 NGA8JV/U
public static void sleep(int nSecond) `# N j8
{ u`%Kh_
try{ Dgb@`oo
Thread.sleep(nSecond); m@|0iDS
} dNQR<v\IL
catch(Exception e) )qgcz<p?W
{ s7x&x;-
e.printStackTrace (); J>H$4t#HX
} ;S+UD~i[Bu
} &$\B&Hp@
4#pn]
//日志 6 WD(
public static void log(String sMsg) ){XaO;k<]
{ ?{@UB*
System.err.println(sMsg); `y1nex-0
} H9@24NFb
TFIP>$*_C
Ec44JD
public static void log(int sMsg) Z6.0X{6nA
{ 9-Y.8:A`
System.err.println(sMsg); 0|1)cO}Dy
} Bh'_@PHP
} )oEHE7y
wt8?@lJ"/
|.OXe!uU41
/* @X_<y
**TestMethod.java *bi!iz5F
*/ [?dsS$Y3
package NetFox; COV8=E~
aP#nK
/-in:gX8
public class TestMethod { fyRSg B00$
T#HW{3
PWch9p0U
public TestMethod() hkifd4#
{ ///xx/weblogic60b2_win.exe S< TUZ /;
try{ rA=iBb3`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 676r0`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); s{"}!y=]
SiteFileFetch fileFetch = new SiteFileFetch(bean); B+8lp4V9%
fileFetch.start(); }^ g6Y3\
} W%6Y?pf)z
catch(Exception e){e.printStackTrace ();} +2qCH^80
vtm?x,h
T@Q,1^?i
} KOYU'hw
;,OZ8g)LH
[]\=(Uc;
public static void main(String[] args) Vr|sRvz
{ 4!l%@R>O2
new TestMethod(); 3 P)N,
} IP#?$X
} j\/Rjn+:[
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