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)); -U2Su|:\N8
} (]q ([e
for(int i=0;i<nEndPos.length-1;i++) <#:iltO
{ oO tjG3B({
nEndPos = nStartPos[i+1]; &E]) sJ0
} %Ik5|\ob?
nEndPos[nEndPos.length-1] = nFileLength; JYc:@\
} s]m]b#1!r
} %72# tY
rPB Ju0D"
t%mi#Gh(
//启动子线程 MEI&]qI
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; RhJ3>DL
for(int i=0;i<nStartPos.length;i++) &3iI\s[
{ \*MZ1Q*x
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L"YQji!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <W!T+sMQj
nStartPos,nEndPos,i); >7WT4l)7!b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iX?j"=!
fileSplitterFetch.start(); .Yk}iHcW.
} 4M"'B A<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ue9d0#9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |}77'w :
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", '@24<T]
nEndPos = " + nFileLength); bD v&;Z
// fileSplitterFetch[nPos.length-1].start(); I]HYqI
Oyb9 ql^
NkUY_rKPb
//等待子线程结束 _oZ3n2v}@
//int count = 0; LiEEQ
//是否结束while循环 @u+LF]MY
boolean breakWhile = false; %{ U (y#
[ (Y@
|$tF{\
while(!bStop) .\`MoH
{ %5L~&W}^"
write_nPos(); &4wSX{c/P
Utility.sleep(500); k6 OO\=
breakWhile = true; E7$ aT^
}Q[U4G
T pCXe\W
for(int i=0;i<nStartPos.length;i++) <DMm [V{
{ XFFm'W6@
if(!fileSplitterFetch.bDownOver) m!INbIh
{ c@lF*"4
breakWhile = false; #+i5'p(4
break; cm!vuoB~~
} 5bZ0}^FYF
} di;~$rI!?
if(breakWhile) Eb,M+c?
break; kJ* N`=
eLH=PDdO
h1'm[Y
//count++; P{RGW.Ci@
//if(count>4) 9n5uO[D
// siteStop(); u$qasII
} 0 Swu]OE
<'T DOYb
(wH+0
System.err.println("文件下载结束！"); [$6YPM>Ee
} ,A#gF_8
catch(Exception e){e.printStackTrace ();} a'q&[08
} t%y i3
s4Jy96<
%f\j)qw
//获得文件长度 ZXj*Vu$_4
public long getFileSize() C,O9?t
{ v)vogtAQa
int nFileLength = -1; !;t6\Z8&
try{ (Ms0pm-#t
URL url = new URL(siteInfoBean.getSSiteURL()); >y!R}`&0^t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TPj,4&|
httpConnection.setRequestProperty("User-Agent","NetFox"); FrRUAoFO
uxX 3wY;M
-g"Wi@Qr
int responseCode=httpConnection.getResponseCode(); Vo%ikR #
if(responseCode>=400) ?:5/4YC
{ <\d`}A:&
processErrorCode(responseCode); @]]\r.DG
return -2; //-2 represent access is error VYK%0S9yH[
} P-Gp^JX8
1Fsa}UK
F)aF.'$-/
String sHeader; u7&5t
z+c8G
nWd;XR6|
for(int i=1;;i++) eS%8WmCV9<
{ &j"_hFhv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zq$0 ?vGd
//Utility.log(in.readLine()); U@}r?!)"f
sHeader=httpConnection.getHeaderFieldKey(i); T0o0_R
if(sHeader!=null) }?CKE<#%
{ 7$Cv=8
if(sHeader.equals("Content-Length")) Q}^qu6
{ Tkj F/zv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *]Eyf")
break; Lu71Qdu09
} t#!AfTY$w
} (2 P&@!|
else Kciz^)'Z
break; (s51GRC
} u`*1OqU
} S""F58H n
catch(IOException e){e.printStackTrace ();} jU{~3Gn?
catch(Exception e){e.printStackTrace ();} 94lz?-j
~'Korxa
US<l4
Utility.log(nFileLength); r+a0.
@><8YN^)%
7Xh ;dJAF3
return nFileLength; +~xzgaL
} ,y)V5 c1
T|--ZRYn
i@=(Y~tD`
//保存下载信息（文件指针位置） Xk:_aJ
private void write_nPos() a!&<jM
{ 0|mCk
try{ BtF7P}:MGf
output = new DataOutputStream(new FileOutputStream(tmpFile)); `nd$6i^#W
output.writeInt(nStartPos.length); 1#XZVp;M
for(int i=0;i<nStartPos.length;i++) ddlF4L_
{ j9f QV
// output.writeLong(nPos); "i%=QON`
output.writeLong(fileSplitterFetch.nStartPos); HC$}KoZkC
output.writeLong(fileSplitterFetch.nEndPos); A4)TJY 3g
} 5_rx$avm
output.close(); /vLW{%
} b~!Q3o'W
catch(IOException e){e.printStackTrace ();} @n$/2y_.
catch(Exception e){e.printStackTrace ();} 2t3)$\ylQp
} AD7&-=p&w
0>3Sn\gZ(
/9ZU_y4&3f
//读取保存的下载信息（文件指针位置） ,/eAns`ZU
private void read_nPos() cZ,}1?!
{ Cv< s|
try{ ^= qL[S6/M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); M?qvI
int nCount = input.readInt(); yh+.Yn=+
nStartPos = new long[nCount]; Y";KWA}b
nEndPos = new long[nCount]; !!)NER-dv
for(int i=0;i<nStartPos.length;i++) r:t3Kf`+E-
{ =BO>Bi&&
nStartPos = input.readLong(); C:vVFU|4
nEndPos = input.readLong(); |cl*wFm|3
} /b."d\
input.close(); 3oPyh $*
} `dgZ`#
catch(IOException e){e.printStackTrace ();} fjqd16{Q
catch(Exception e){e.printStackTrace ();} O]?PC^GGY
} !)EYM&:Y
% 3<7HY]~
15kkf~Z<t
private void processErrorCode(int nErrorCode) Pu,2a+0N
{ 3 t+1M
System.err.println("Error Code : " + nErrorCode); V?n=yg
} 7J|nqr`>t
]4,eCT
Ime"}*9
//停止文件下载 PebyH"M(
public void siteStop() ~Vf A
{ wu0q.]
bStop = true; a6"-,Kg
for(int i=0;i<nStartPos.length;i++) $v1_M1
fileSplitterFetch.splitterStop(); H ;)B5C
0\wW%3C
.i3_D??
} xC 4L`\
} m(^nG_eX
//负责部分文件的抓取 2I_~]X53[
**FileSplitterFetch.java CTQJ=R"
*/ ~L"?C
package NetFox; =tc!"{
)< p ~
^]?juL
import java.io.*; bg^<e}{<H
import java.net.*; {vp*m:K
[G"Va_A8
5Rae?*XH
public class FileSplitterFetch extends Thread { kTm}VTr 1
C~04#z_$
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String sURL; //File URL aqv'c j>
long nStartPos; //File Snippet Start Position [=^Wj`;
long nEndPos; //File Snippet End Position a2eE!I
int nThreadID; //Thread's ID ,hE989x<iI
boolean bDownOver = false; //Downing is over _>4)q=
boolean bStop = false; //Stop identical U,Fyi6{~
FileAccessI fileAccessI = null; //File Access interface ^`bMFsP
c-ql
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v4,Dt
{ *$@u`nM
this.sURL = sURL; Yzw[.(jc}
this.nStartPos = nStart; JgBC:t^\pV
this.nEndPos = nEnd; rbrh;\<jM
nThreadID = id; ?$VkMu$2k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M<P8u`)>4H
} :a9
tNz(s)
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public void run() ==EB\>g|
{ 4u#TKr.
while(nStartPos < nEndPos && !bStop) H^M>(kT#&
{ @I#uv|=N
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dj{~!}
try{ 0!M'z
URL url = new URL(sURL); >+):eBL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P=Su)c
httpConnection.setRequestProperty("User-Agent","NetFox"); z#2n+hwE
String sProperty = "bytes="+nStartPos+"-"; |^"0bu"
httpConnection.setRequestProperty("RANGE",sProperty); S:1g(f*85
Utility.log(sProperty); ,(NN)Oj
h=B= J
>~_)2_j
InputStream input = httpConnection.getInputStream(); -B?cF9
//logResponseHead(httpConnection); N! I$Qtr,
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L2OR<3*|Av
byte[] b = new byte[1024]; J M`[|"R%
int nRead; Rx?ze(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I moxg+u
{ my#\(E+
nStartPos += fileAccessI.write(b,0,nRead); R[@}Lg7+v
//if(nThreadID == 1) Zpz3?VM(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ilAhw4A
} d0;?GQYn:
V)P8w#,
%< `D'V@
Utility.log("Thread " + nThreadID + " is over!"); 9dWz3b1[]
bDownOver = true; `\f 3Ij,
//nPos = fileAccessI.write (b,0,nRead); 9*r^1PRc
} cZ#%tT#
catch(Exception e){e.printStackTrace ();} .eLd0{JtN
} mv^X{T
} :[7O=[pk
l2I%$|)d
SYa O'c
//打印回应的头信息 %`YR+J/V
public void logResponseHead(HttpURLConnection con) [2E(3`-u
{ h`iOs>
for(int i=1;;i++) Hz)i.AA 4
{ u08QE,
String header=con.getHeaderFieldKey(i); h J0U-m
if(header!=null) $tej~xZK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %r8;i
Utility.log(header+" : "+con.getHeaderField(header)); g/VV2^,
else <y?=;54a
break; `evF?t11X
} &xUD(
} qHvUBx0
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J_?v=dW`
public void splitterStop() :Qhrh(i
{ b'Km-'MtH
bStop = true; "p7nngn~
} U_l9CZ
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v*%52_
} ESYF4-d+
V@[C=K
{Wu[e,p
/* n4y]h
**FileAccess.java fP\q?X@]E
*//文件访问(定位，写) 8KYIHw
package NetFox; 8QoxU" c&
import java.io.*; x0WinLQ
gY8$Rk %
57-Hx;
public class FileAccessI implements Serializable{ *l=(?Pe<
Eku9u
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RB|i<`Z
RandomAccessFile oSavedFile; Wky9wr:g
long nPos; -$DfnAh
v; R2,`[W
xiDgQTDz
public FileAccessI() throws IOException 8;r#HtFM
{ *0to,$ n
this("",0); 4QTHBT+2`
} ;j7G$s9
.6xMLo,R
|<5F08]v
public FileAccessI(String sName,long nPos) throws IOException U7?v4O]D[
{ ixSr*+
oSavedFile = new RandomAccessFile(sName,"rw"); =*"8N-FU
this.nPos = nPos; ]Yw$A
oSavedFile.seek(nPos); ts9wSx~[+
} a[ayr$Hk?
^ nI2<P
GEA1y^b6"
public synchronized int write(byte[] b,int nStart,int nLen) g,rmGu3v
{ _DH^ K9,9
int n = -1; gWzslgO6
try{ RB4 +"QUh
oSavedFile.write(b,nStart,nLen); _+'!l'`
n = nLen; -Ep#q&\
} %,~?;JAj
catch(IOException e) P_w4 DU
{ ".N+nM~
e.printStackTrace (); ]%FAJ\
} a4*976~![
p6R+t]oH
zX4RqI
return n; N+@ Ff3M
} }Sbk qd5
yDwh]t
7HBf^N.
} r9OgezER
JE7m5kTa
f?51sr
/* dGn0-l'q
**SiteInfoBean.java eqsmv[
*/ j~G(7t
package NetFox; rpK&OR/
)N8bOI
h]s~w
public class SiteInfoBean { eNK[P=-
OtmDZ.t;`
75zU,0"j
private String sSiteURL; //Site's URL 2Y23!hw
private String sFilePath; //Saved File's Path |w}j!}u
private String sFileName; //Saved File's Name dN)8r
private int nSplitter; //Count of Splited Downloading File T7.Iqw3p
@$ Zh^+x!
Z17b=xJw
public SiteInfoBean() BZ1wE1t
{//nSplitter的缺省值为5 5P%#5Yr2
//default value of nSplitter is 5 d#a/J.Z$A
this("","","",5); ~x\uZ^:
} >&KH!:OX|
9<.O=-1~
[ gMn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e;"J,7@
{ E|"SMA,
sSiteURL= sURL; KE~Q88s
sFilePath = sPath; YHQ]]#'
sFileName = sName; 3HpqMz
this.nSplitter = nSpiltter; M7cD!s@'I
i[IFD]Xy!j
Lo{wTYt:J
} ,"(G
)>:~XA|?
A}(]J!rc
public String getSSiteURL() pE)NSZ
{ Ee2P]4_d
return sSiteURL; "u!gfG?oH
} dX cbS<
QQ.?A(U7
\+%~7Bi]z
public void setSSiteURL(String value) ~p?ArZb
{ XNWtX-[^@
sSiteURL = value; e^>>"tr
} ;+E]F8G9r
'7sf)0\:<p
PJC(:R(j
public String getSFilePath() <-`.u`
{ ,%*UF6B M
return sFilePath; BX0lk
} $h{m")]
:^3)[.m
;rT'~?q
public void setSFilePath(String value) Y:ly x-lj
{ e=OHO,74z"
sFilePath = value; $lJcC |*
} /=m AVA
(yqe4
DJ,LQj
public String getSFileName() i *.Y
{ sip4,>,E
return sFileName; UJI2L-;Ul
} 6MT (k:
SWV*w[X<X
U.Mfu9}#:
public void setSFileName(String value) )OV0YfO
{ [! $NTt_
sFileName = value; Y7}Tuy dC
} 7z4k5d<^_
o{sv<$
xR0T'@q
public int getNSplitter() -<s Gu9
{ ^el+ej/=
return nSplitter; \N*([{X
} 9E2iZt]
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public void setNSplitter(int nCount) CLrX!JV>
{ ?IVJ#6[
nSplitter = nCount; U"k$qZ[
} -+rzc&h
} W\~^*ny P6
,IjZQ53q~
qgrJi +WZ
/* U|} ?{x
**Utility.java VV$t*9w
*/ ,/{e%J
package NetFox; ?uq`|1`
gm-[x5O"
WPL@v+
public class Utility { kcCCa@~v
^HC6v;K
6eV#x%z@v'
public Utility() EnM
{ .HS6DOQ
oFWb.t9<
t5-O-AI[b{
} B}iEhWO6
h3CA,$HJ
//线程睡眠 SndR:{
public static void sleep(int nSecond) )!"fUz$
{ +-!E%$
try{ S\A/*!%~y
Thread.sleep(nSecond); X2|~(*
} U g"W6`
catch(Exception e) (I>Ch)'
{ D@bGJc0
e.printStackTrace (); 0B`X056|"|
} tqGrhOt
} JXB)'d0
w>%@Ug["
//日志 wh8';LZ>R
public static void log(String sMsg) cV+?j}"*+
{ gg/`{
System.err.println(sMsg); 4@PA+(kvS
} dJ"M#X!Zu
'#'noB;,
4VJUu`[
public static void log(int sMsg) `L'g<VK;
{ RxP H[7oZ
System.err.println(sMsg); yix[zfQt0
} 6zi>Q?] 1
} <CyU9`ye
]q]xU,
AQ~ xjU
/* G!q[NRu
**TestMethod.java IO\4dU)
*/ o:Fq|?/e
package NetFox; !zA@{gvEc
oW3"J6,S
m@Z#
public class TestMethod { $h#sb4ek
o`bc/3!
Og\k5.! ,
public TestMethod() 9bM\ (s/
{ ///xx/weblogic60b2_win.exe <Riz!(G
try{ 5C Dk5B_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Met]|&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F$7!j$ Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); _'=,c"
fileFetch.start(); >P/36'
} k#].nQG
catch(Exception e){e.printStackTrace ();} QZzamT)"
_ \D%
w*qj0:i5as
} =XP[3~
4zoQe>v~
'2(m%X\6
public static void main(String[] args) HlGSt$woX
{ lzEynMO+
new TestMethod(); Gw*Tz"
} {&51@UX
} /(dP)ysc
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