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)); "_jczr$*
} 7)G- EAF
for(int i=0;i<nEndPos.length-1;i++) ~d_Z?Z
{ f5zxy!dhKS
nEndPos = nStartPos[i+1]; H?ssV^k
} 4\<[y]pv
nEndPos[nEndPos.length-1] = nFileLength; 2;.7c+r0
} -fVeE<[
} N8:?Z#z
nU%rSASu
u9}}}UN!
//启动子线程 8m1@l$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; f33'2PYl
for(int i=0;i<nStartPos.length;i++) $6atr-Pb
{ 95^w" [}4Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h";G vjy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ("o<D{A
nStartPos,nEndPos,i); Y>Q9?>}Q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P"W$ZX
fileSplitterFetch.start(); ORlz1&hW
} HH+NNSRO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |{cdXbr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /ow/)\/}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |//cA2@.
nEndPos = " + nFileLength); sl-LX)*N#
// fileSplitterFetch[nPos.length-1].start(); T=:&W3
^sd+s ~xx
y.5mYQA4=[
//等待子线程结束 N!m-gymmF
//int count = 0; IJO`"da
//是否结束while循环 "QACQ-
boolean breakWhile = false; Fgxh?Wd9
hJ#U;GL
~\DC )
while(!bStop) ~}w(YQy=y
{ sIdo(`8$
write_nPos(); l*("[?>I
Utility.sleep(500); N:[m,U9a
breakWhile = true; -vwkvNn8
g"( vl-Uw
Y'Sxehx
for(int i=0;i<nStartPos.length;i++) ?mS798=f
{ 4JFi|oK0H
if(!fileSplitterFetch.bDownOver) &M=12>ah]
{ Ki}PO`s
breakWhile = false; }qT @.
break; Hkg^
} 6G7B&"&
} z,}1K!
if(breakWhile) c>{X(Z=2
break; )y'`C@ijI
r vVU5zA4H
e{U`^ao`F8
//count++; IB /.i(
//if(count>4) QkZT%!7
// siteStop(); o1MI&}r
} b*qkox;j
%~J90a
g$kK)z
System.err.println("文件下载结束！"); ~el#pf~
} wKe^5|Rr
catch(Exception e){e.printStackTrace ();} (\.[pj%-O
} &D[dDUdHs
KM< +9`
YTQ|Hg6jO
//获得文件长度 D; H</5#Q
public long getFileSize() vTQQd@
{ ^2|gQ'7<
int nFileLength = -1; uCF+Mp
try{ 7<x0LW
URL url = new URL(siteInfoBean.getSSiteURL()); AUcq\Ys
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |OF<=GGO+
httpConnection.setRequestProperty("User-Agent","NetFox"); ;#78`x2
7!hL(k[
Q{b ZD*
int responseCode=httpConnection.getResponseCode(); +`u]LOAyP=
if(responseCode>=400) r-'\<d(J$
{ yfiRMN"2
processErrorCode(responseCode); ;5ugnVXu
return -2; //-2 represent access is error RPPxiYU^
} I/jMe'Kp
IE: x&q`3
G%;XJsFGp
String sHeader; Kl{2^q>
lg&"=VXx51
%;^[WT`,
for(int i=1;;i++) 5*[zIKdt2
{ R+P,kD?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %Ub"V\1
//Utility.log(in.readLine()); C"k8M\RW?
sHeader=httpConnection.getHeaderFieldKey(i); )9##mUt'}
if(sHeader!=null) JxiLjvIq
{ f|WNPFQ$x
if(sHeader.equals("Content-Length")) 'SYjEhvw
{ E0\ '
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qc|;qPj
break; E,shTh%&~
} K:z|1V
} x^8xz5:O
else dwv xV$Nt
break; #p&iH9c_
} u3Z*hs)Z%
} 6vro:`R ?
catch(IOException e){e.printStackTrace ();} /$\yAOA'y
catch(Exception e){e.printStackTrace ();} k)Z?
%<O'\&!,
7.CzS
Utility.log(nFileLength); j7<`^OG
]x:>~0/L
VhT4c+Zs
return nFileLength; "Vho`x3
} y^Oj4Y:
G'MYTq
FlOKTY
//保存下载信息（文件指针位置） W>K2d
private void write_nPos() zv <,
{ r-^Ju6w{
try{ ggVB8QN{
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ag }hyIl
output.writeInt(nStartPos.length); ?qAX *j
for(int i=0;i<nStartPos.length;i++) ]n${j/x
{ Ec8Y}C,{7<
// output.writeLong(nPos); cInzwdh7
output.writeLong(fileSplitterFetch.nStartPos); BqvOi~l
output.writeLong(fileSplitterFetch.nEndPos); gmLGK1
} yrR<F5xge
output.close(); RQy|W}d_
} ?CAP8_
catch(IOException e){e.printStackTrace ();} J^hj R%H
catch(Exception e){e.printStackTrace ();} S-gL]r3G8
} ?#ndMv!$
ZL#4X*zT
L;Nz\sJ
//读取保存的下载信息（文件指针位置） , =IbZ
private void read_nPos() ']u w,b
{ *ls}r5k2Y
try{ }!pC}m
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $7jJV(B
int nCount = input.readInt(); (+4gq6b
nStartPos = new long[nCount]; w?Nvm?_]
nEndPos = new long[nCount]; qXt2m
for(int i=0;i<nStartPos.length;i++) cm%QV?
{ t&mw@bj
nStartPos = input.readLong(); Z7JI4"
nEndPos = input.readLong(); +NxEx/{
} llhJ,wD
input.close(); (nbqL+
} _I<eJ\
catch(IOException e){e.printStackTrace ();} [ k^6#TQcn
catch(Exception e){e.printStackTrace ();} $bF.6
} Y{1IRP?S
JiDX|Q<c
kFHqQsaG
private void processErrorCode(int nErrorCode) WUQ2[)<
{ kR%CSLOVy
System.err.println("Error Code : " + nErrorCode); N12K*P[!
} 1jh^-d5
NVS U)#
)$P!7$C-
//停止文件下载 r5(OH3
public void siteStop() `dMOBYV
{ g`y >)N/
bStop = true; }pu2/44=W
for(int i=0;i<nStartPos.length;i++) 4Yt:PN2
fileSplitterFetch.splitterStop(); F04`MY"
&~6Z)}
1e'-rm F
} xh#ef=Bw
} JZD27[b
//负责部分文件的抓取 uDafPTF
**FileSplitterFetch.java /cJ$` pN
*/ Fr,>|
package NetFox; NJz8ANpro$
jsf=S{^2
Z]1~9:7ap
import java.io.*; YCeE?S1gk3
import java.net.*; ZJP.-`U
TiCp2Rsz
gA2Il8K
public class FileSplitterFetch extends Thread { .7g^w+W
NjdAfgA
-J:](p
String sURL; //File URL G-Sw`HHo
long nStartPos; //File Snippet Start Position e3F)FTG&
long nEndPos; //File Snippet End Position #fG!dD42
int nThreadID; //Thread's ID H[*.Jd
boolean bDownOver = false; //Downing is over .m7iXd{
boolean bStop = false; //Stop identical *Y9"-C+
FileAccessI fileAccessI = null; //File Access interface bNFX+GA/
&Km?(%?
c<A@Op"A
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7_E+y$i=
{ 6^mO<nB
this.sURL = sURL; HMgZ&v
this.nStartPos = nStart; WWrDr
this.nEndPos = nEnd; !!o69
nThreadID = id; 5A7!Xd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |42E'zH&
} _:c8YJEG{
<hZA$.W3
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public void run() *.Y!ZaK
{ @xtcjB9
while(nStartPos < nEndPos && !bStop) L G,XhN
{ =Q.2:*d.
OB6I8n XW
l#~Sh3@L(
try{ t<|=-
URL url = new URL(sURL); hAfRHd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )}~k7bb}Y
httpConnection.setRequestProperty("User-Agent","NetFox"); zXbTpm
String sProperty = "bytes="+nStartPos+"-"; vo!:uvy;2
httpConnection.setRequestProperty("RANGE",sProperty); KVtnz
Utility.log(sProperty); uTbI\iq
qOZc}J0
AcrbR&cvG
InputStream input = httpConnection.getInputStream(); >P>.j+o/
//logResponseHead(httpConnection); cw/g1,p
9D(M>'Bh
@2CYv>
byte[] b = new byte[1024]; /w_Sc{
int nRead; H^K(1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Rk"VFe>r
{ viD+~j18
nStartPos += fileAccessI.write(b,0,nRead); , *e^,|#
//if(nThreadID == 1) 67 7p9{:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0w8Id . ,
} ,{%/$7)
wjq f u /
5>KAVtYvc
Utility.log("Thread " + nThreadID + " is over!"); H<}<f:
bDownOver = true; 0>H<6Ja
//nPos = fileAccessI.write (b,0,nRead); ItYG9a
} /A_</GYs
catch(Exception e){e.printStackTrace ();} A. U<
} @`wBe#+\
} q jDWA'
P6i4Dr
KbMgatI/
//打印回应的头信息 X[j4V<4O
public void logResponseHead(HttpURLConnection con) gBYL.^H^l
{ Hi,_qlc+
for(int i=1;;i++) m ~fqZK
{ _#f/VE
String header=con.getHeaderFieldKey(i); q,aWF5m@
if(header!=null) iBN,YPo~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9^v|~f
Utility.log(header+" : "+con.getHeaderField(header)); ?Sn$AS I
else ;L(W'+
break; ?7^('
} .N_0rPO,Kw
} kzJNdYtdH
jtQ2vJ-
|A'8'z&q
public void splitterStop() R!*UU'se
{ t Z\
bStop = true; f:Nfw+/q
} F mh;d*IT
w,eYrxR|N
UQ'D-eK
} %CF(SK2w
-T4?5T_
:/~`"`#1
/* Haj`mc!<D0
**FileAccess.java >bz}IcZP
*//文件访问(定位，写) IJS9%m#
package NetFox; .A\9|sRZ5
import java.io.*; fAUtqkB
0u'2f`p*
(W=z0Lqu
public class FileAccessI implements Serializable{ OjJlGElw
(mt,:hX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [g=yuVXNZZ
RandomAccessFile oSavedFile; }4cLU.L8O
long nPos; $o/?R]h
J:#B,2F+^
oF]0o`U&a
public FileAccessI() throws IOException E`LML?
{ Fd5{pM3
this("",0); vq(@B
} "4`h -Y
l= ~]MSwY
>W.Pg`'D
public FileAccessI(String sName,long nPos) throws IOException B964#4& 9
{ >I]t|RT])
oSavedFile = new RandomAccessFile(sName,"rw"); Z7k {7
this.nPos = nPos; 5y}}?6n+
oSavedFile.seek(nPos); .[= 0(NO
} -M%n<,XN0
Pk~P
ZN%$k-2
public synchronized int write(byte[] b,int nStart,int nLen) 'V 1QuSd
{ kSB)}q6a
int n = -1; FK@rZP
try{ j\@s pbE@
oSavedFile.write(b,nStart,nLen); iknBc-TLD
n = nLen; )3h=V^rm
} Q&`$:h.~
catch(IOException e) ^tc@bsUF
{ {r[*}Bv
e.printStackTrace (); WZ6!VE{
} JY9Hqf
cU%#oEMf<
uZm<:d2%)
return n; D~NH 4B
} dfc-#I p?
FEU$D\1y
Lkqu"V
} 2#T|+mKxZM
r'{pTgm#
kRSu6r9
/* 'PV,c|f>
**SiteInfoBean.java JS({au
*/ *bmk(%g
package NetFox; A){kitx-i)
I0m/
@iC!Q>D
public class SiteInfoBean { J>!p^|S{
)bi*y`UM]
@hl5^d"l
private String sSiteURL; //Site's URL VI" ,E}
private String sFilePath; //Saved File's Path =2J+}ac
private String sFileName; //Saved File's Name ,0lRs
private int nSplitter; //Count of Splited Downloading File sGMC$%e}
"o;l8$)VL
X*$ 7g;
public SiteInfoBean() 2$qeNy
{//nSplitter的缺省值为5 pOIFO=k
//default value of nSplitter is 5 +;FF0_
this("","","",5); "Q2[A]4E
} h^x7[qe
<adu^5BI
.?!{.D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gTO%
{ C(e!cOG
sSiteURL= sURL; ]$0{PBndW
sFilePath = sPath; ;)"r^M)):
sFileName = sName; MSRIG-
this.nSplitter = nSpiltter; 5A~w_p*}
3w!oJB
wpx,~`&
} )z7.S"U
P63z8^y
if#$wm%
public String getSSiteURL() g>OGh o
{ k?|VFh1
return sSiteURL; ScZ$&n
} N;r,B
rd%3eR?V
d 'x;]#S
public void setSSiteURL(String value) X=${`n%LG
{ c7wza/r>
sSiteURL = value; `1M_rG1/+
} uZ<Bfrc
~g1@-)zYxK
Qbt fKn95
public String getSFilePath() |])%yRAGQ
{ ,1^)JshZ~
return sFilePath; zs[t<`2
} ^C<dr}8
h>bmHQ
Y<a/(`
public void setSFilePath(String value) ^6J*yV%
{ =jg!@H=_i
sFilePath = value; Y*wbFL6`
} 9Ki86
.}Bb :*@
-cY/M~
public String getSFileName() 0A5xG&
{ {D`F$=Dlw
return sFileName; 'DntZK
} 0vQkm<
"]zq<LmX
D=9x/ ) *G
public void setSFileName(String value) ,!sAr;Rk`
{ 2HQHC]
sFileName = value; [>C^ 0\Z~
} ag|d_;
mI0|lp 1$
ks(PH6:]<
public int getNSplitter() pSV 8!
{ z81I2?v[Jr
return nSplitter; BtU,1`El5
} r~t&;yRv
4XX21<yn
M7jDV|Go
public void setNSplitter(int nCount) R8":1 #&
{ c!w4N5aM
nSplitter = nCount; :*}tkr4&eh
} ~a/yLI"'g
} &,NHk9.aq
Zh3]bg5
3bE^[V8/
/* W=F?+KgL
**Utility.java [0)iY%^
*/ eYsO%y\I
package NetFox; W{Nhh3
QbOmJQ
QD\S E
public class Utility { RsTpjY*Xb
3 5|5|ma
)I!l:!Ij*D
public Utility() 8MW|CM4Q
{ \%^<Ll
g*Cs/w
2Ybz`O!
} ,:=E+sS
"#[Y[t\Ia
//线程睡眠 x`C;
public static void sleep(int nSecond) k`\DC\0RG
{ CgEeO,N]j
try{ 7p u*/W~
Thread.sleep(nSecond); C_'Ug
} {&K#~[)
catch(Exception e) [Hn+r&
{ (CuaBHR
e.printStackTrace (); ^IQC:21
} 3=;iC6 `
} W-Hw%bwN/q
VZ_4B *D
//日志 J5|Dduv
public static void log(String sMsg) o^DiIoor
{ Zu~ #d)l3N
System.err.println(sMsg); U R@'J@V#:
} ''f
^f3F~XhY3
sVh!5fby&
public static void log(int sMsg) kFuaLEJi
{ gI\J sN
System.err.println(sMsg); oleRQ=
} LX*T<|c`'
} `"-)ObOj}
OmKT}D~ 4
Q6}`%
/* K 7YpGGd5
**TestMethod.java b?HW6Kfc
*/ if^\Gs$
package NetFox; jL`S6E?7
r,yhc =
|? r,W~9`
public class TestMethod { ].:S!QO
(M5=8g%>d
>@TZYdl
public TestMethod() !>t|vgW
{ ///xx/weblogic60b2_win.exe rJ!xzge;G
try{ =A=er1~%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .F 3v)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2v%~KV
SiteFileFetch fileFetch = new SiteFileFetch(bean); GHYgSS
fileFetch.start(); Kr]F+erJe
} LvW9kL+WiQ
catch(Exception e){e.printStackTrace ();} (Ptv#LSUX
S=M$g#X`5
&x;v&
} <R]?8L0{h
B8B^@
^>k[T.
public static void main(String[] args) wU+ofj; +I
{ m_(+-G
new TestMethod(); WW==
} =xa`)#4(
} :X2B+}6_&
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