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)); 3@etRd;]Kr
} \\iQEy<i
for(int i=0;i<nEndPos.length-1;i++) &PR5q7
{ ]~Rho_mq#
nEndPos = nStartPos[i+1]; JrJo|0Q
} kKaE=H-x
nEndPos[nEndPos.length-1] = nFileLength; Vh'P&W?[
} S]}nm
} %|s;C
[`ebM,W
l.q&D< _
//启动子线程 vLv@&lMW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kjTduZ/3"
for(int i=0;i<nStartPos.length;i++) {DV_*5
{ UFXaEl}R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B{QBzx1L9c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), T;Lkaxsn
nStartPos,nEndPos,i); w#ZoZZ wh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5dx$HE&b)
fileSplitterFetch.start(); -RE^tW*Yy
} 3atBX5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), { }:#G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1h^:[[!c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m]'#t)B_m
nEndPos = " + nFileLength); y*4=c_Z
// fileSplitterFetch[nPos.length-1].start(); :vmH]{R
GSoX<*i
RVZ")Z(
//等待子线程结束 $h+1u$po
//int count = 0; .T}Wdng
//是否结束while循环 QVv#fy1"6
boolean breakWhile = false; Q1U\D
h=W:^@G
%:M^4~dc
while(!bStop) ${<%" hR$
{ W =D4r
write_nPos(); 6|gCuT4
Utility.sleep(500); TJ2=m9Z
breakWhile = true; {0[tNth'h
>BV^H.SO|1
x) ,eI'mf
for(int i=0;i<nStartPos.length;i++) ]3D0R;
{ :N:yLd} &
if(!fileSplitterFetch.bDownOver) _('=b/
{ qEyyT[:
breakWhile = false; Z_LFIz*c
break; ^P[e1?SZG
} g?c xp+
} NN%*b yK
if(breakWhile) h){0rX@:&
break; ?k+xSV
[u =+3b
X1DF*wI
//count++; &xU[E!2H%
//if(count>4) ZJnYIK
// siteStop(); cutuDZ
} Q$a{\*[:+
+! ]zA4x
6]&OrS[
System.err.println("文件下载结束！"); .6ylZ
} evya7^,F
catch(Exception e){e.printStackTrace ();} 3$jT*OyG#
} )cX*I gO
Ab~3{Q]#
qFicBpB
//获得文件长度 G'nmllB`]
public long getFileSize() Q3XpHnufu+
{ 1rNzJ;'
int nFileLength = -1; =T3<gGM
try{ |.(dq^
URL url = new URL(siteInfoBean.getSSiteURL()); ]Oe2JfJwx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [T|aw1SoN
httpConnection.setRequestProperty("User-Agent","NetFox"); t=BUN
N+9VYH"*
)~GmU9f
int responseCode=httpConnection.getResponseCode(); #%pI(,o=
if(responseCode>=400) J-[,KME_^
{ OsTc5K.U~
processErrorCode(responseCode); H[NSqu.s
return -2; //-2 represent access is error 7!evm;A
} ntu5{L'8
v3*_9e
D.r<QO~6B
String sHeader; 2+RUTOv/d
yjO1 Ol
.Hescg/S
for(int i=1;;i++) Rm2yPuOU}A
{ ~G)S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); I )~GZ
//Utility.log(in.readLine()); ;d@#XIS&-(
sHeader=httpConnection.getHeaderFieldKey(i); 'S20\hwt-
if(sHeader!=null) 3#WT.4k
{ h!M
if(sHeader.equals("Content-Length")) %Si6]3-^@
{ To\QjP-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X1:V<,}"
break; aFl;BhM
} i"1Mfz~e
} O+nEXS\rQ
else Wt*cIZ
break; v>6"j1Z
} JOj;^h
} 0B[="rTS7#
catch(IOException e){e.printStackTrace ();} v|Pv 03%?7
catch(Exception e){e.printStackTrace ();} bYcV$KJk
{IjF+@I
q?H|o(
Utility.log(nFileLength); Z@yW bjE7Z
3>3Kwc~E
D+#E-8
return nFileLength; *-#&K\
} Ij 79~pn
$6qh| >z.
gLb`pCo/
//保存下载信息（文件指针位置） 2ElJbN#
private void write_nPos() ~b(i&DVK
{ @tF\p
try{ \|n- O=}=2
output = new DataOutputStream(new FileOutputStream(tmpFile)); gGR"Z]DBk
output.writeInt(nStartPos.length); EHSlK5bD,
for(int i=0;i<nStartPos.length;i++) OP;v bZ
{ _Mi5g_
// output.writeLong(nPos); j9m_jv
output.writeLong(fileSplitterFetch.nStartPos); ~Q*%DRd&Z-
output.writeLong(fileSplitterFetch.nEndPos); >|J`s~?
} \0A3]l
output.close(); hl;u'_AB
} seba9y
catch(IOException e){e.printStackTrace ();} 4aug{}h("
catch(Exception e){e.printStackTrace ();} [Hx0`Nc K
} tCw<Ip
%3s1z<;R[S
*}Xf!"I#]N
//读取保存的下载信息（文件指针位置） :Oy%a'w
private void read_nPos() 36.Z0Z1'F>
{ ke!?BZx
try{ 2"COP>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MO[2~`,Q!
int nCount = input.readInt(); T!uM+6|Y
nStartPos = new long[nCount]; QER?i;-wb
nEndPos = new long[nCount]; H h4WMZJG
for(int i=0;i<nStartPos.length;i++) \h+AXs<j
{ JX<)EZ!F
nStartPos = input.readLong(); ;[(oaK@+n
nEndPos = input.readLong(); y$;/Vm_'
} []D&bYpv
input.close(); cv8L-Z>x.=
} 3v(*5
catch(IOException e){e.printStackTrace ();} Pi=+/}
catch(Exception e){e.printStackTrace ();} ;$HftG>B
} x-XD.qh7Hr
Z~GL5]S
},uF4M.K
private void processErrorCode(int nErrorCode) f0!))/rSD
{ 6d:zb;Iz
System.err.println("Error Code : " + nErrorCode); %Celc#v
} Ii6<b6-
AWcLUe{
p}&#jE
//停止文件下载 "<6G6?sz
public void siteStop() 5CuuG<0
{ X3(tuqmi
bStop = true; a,Sw4yJ!Q
for(int i=0;i<nStartPos.length;i++) |U~<3.:m:
fileSplitterFetch.splitterStop(); lVd^ ^T*fh
84$nT>c
[m+2(I1
} iyN:%ofh
} 02Y]`CXj
//负责部分文件的抓取 ~Cbc<[}
**FileSplitterFetch.java AJt+p&I[J
*/ iky|Tp
package NetFox; w?3p';C
ysJQb~2q
>u>5{4
import java.io.*; 4Xgg%@C
import java.net.*; >1s* at/h
>/{@C
w2Us!<x
public class FileSplitterFetch extends Thread { &]V.S7LC#
Y1L[;)Hn
Uq[>_"}
String sURL; //File URL Q_1:tW &
long nStartPos; //File Snippet Start Position m&xW6!x
long nEndPos; //File Snippet End Position ``V" D
int nThreadID; //Thread's ID Y)1PB+
boolean bDownOver = false; //Downing is over lvdf^b/ j
boolean bStop = false; //Stop identical 9Q.rMs>qj
FileAccessI fileAccessI = null; //File Access interface #r$cyV!k
2$9odD<r
9eR-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *jLJcb*.Ap
{ tI]Q%S,
this.sURL = sURL; $:BKzHmg
this.nStartPos = nStart; l~1Oef#y
this.nEndPos = nEnd; &]g}u5J!=
nThreadID = id; -O1>|y2rU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bNm#tmSt
} ICpAt~3[M
jGJLSEe_
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public void run() 2^Eg9y'
{ t\?ik6
while(nStartPos < nEndPos && !bStop) mGtdO/C#B
{ FFl!\y*0z
NYt&@Z}]
s0\X ^
try{ ? 8)'oMD
URL url = new URL(sURL); Jk&3%^P{m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); neB\q[k
httpConnection.setRequestProperty("User-Agent","NetFox"); 6q*9[<8
String sProperty = "bytes="+nStartPos+"-"; eS{!)j_^
httpConnection.setRequestProperty("RANGE",sProperty); k\wW##=v
Utility.log(sProperty); "76]u)
<W|3\p6
cq5jPZ}
InputStream input = httpConnection.getInputStream(); 1G"z<v B
//logResponseHead(httpConnection); ;}7Rjl#
l2`s! ,<>O
"K ~
byte[] b = new byte[1024]; [V^WGW2oY
int nRead; |"?M1*g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FI[A[*fi
{ w&X<5'GM
nStartPos += fileAccessI.write(b,0,nRead); ccB&O _
//if(nThreadID == 1) pSoiH<33
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +GG9^:<yr
} 8R2QZXJb-
Jy^u?
>5_2_Y$"
Utility.log("Thread " + nThreadID + " is over!"); a<@1-j<
bDownOver = true; ztnFhJ<a$
//nPos = fileAccessI.write (b,0,nRead); MPCBT!o4Z
} M:XSQ["6>V
catch(Exception e){e.printStackTrace ();} U [*FCD!~
} qT,Te
} fg s!v7
5"^en# ?9
:imW\@u
//打印回应的头信息 ?QsQnQ
public void logResponseHead(HttpURLConnection con) VkvB<3
{ E4xj?m^(y=
for(int i=1;;i++) |P[w==AAf
{ ,eOB(?Ku
String header=con.getHeaderFieldKey(i); C+'/>=>a.
if(header!=null) (XeE2l2M
//responseHeaders.put(header,httpConnection.getHeaderField(header)); LyZ.l*h%=m
Utility.log(header+" : "+con.getHeaderField(header)); zer%W%
else vBRQp&YwX
break; J3,fk)
} !i{aMxUP
} Z LB4m`
OPwtV9%
.}^g!jm~h
public void splitterStop() j\,EO+ZQCv
{ L\Aq6q@c
bStop = true; 9`wZz~hL"
} <nE>XAI_7
`q?8A3A
BZ:H`M`n
} --PtZ]Z
A$<.a'&T!
@AGn{q
/* X59:C3c
**FileAccess.java 0":ib0=
*//文件访问(定位，写) T29Dt
package NetFox; JF # # [O
import java.io.*; mZk]l5Lc
XR+Y=R
0C1pt5K
public class FileAccessI implements Serializable{ o4j[p3$
cimp/n"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %{ABaeb]
RandomAccessFile oSavedFile; d^RxQuA
long nPos; IHe/xQ@
#,,d>e
>{N9kWY
public FileAccessI() throws IOException Kh,V.+7k
{ C3eR)Yh
this("",0); }x@2]juJ
} i'4B3
(0j}-iaQEZ
s@9vY\5[9
public FileAccessI(String sName,long nPos) throws IOException { D^{[I
{ _]yn"p
oSavedFile = new RandomAccessFile(sName,"rw"); HIQ_%L4]
this.nPos = nPos; 0KYEb%44
oSavedFile.seek(nPos); nTuJEFn{
} IAYR+c
,-izEr
D&/kCi=R
public synchronized int write(byte[] b,int nStart,int nLen) k,'L}SK
{ 87Oad@FOr
int n = -1; uZc`jNc\
try{ G"\`r* O
oSavedFile.write(b,nStart,nLen); #z&&M"*a|
n = nLen; X*M#FT-
} |kw)KEi}H
catch(IOException e) UF?H>Y&
{ iTFdN}U
e.printStackTrace (); )0ea+ib
} (5#nrF]
0*rQ3Z
N03HQp)g
return n; 2r!s*b\Ix
} Zw*v
)^m%i]L_
4#ug]X4Y')
} 8)O[Aq::
bu |a0h7e
ERpnuMb
/* hJn%mdx~w|
**SiteInfoBean.java crqpV F]1]
*/ V=zi >o`
package NetFox; Y,WuBH
"5-^l.CKH
V^JV4 `o
public class SiteInfoBean { N F2/B#q
S'A>2>
3{ LP?w:@
private String sSiteURL; //Site's URL 1y-y6q
private String sFilePath; //Saved File's Path /4c\K-Z;
private String sFileName; //Saved File's Name Jd%H2`
private int nSplitter; //Count of Splited Downloading File Fz1_w$^
f#?fxUH~
h!&prYx
public SiteInfoBean() {U!8|(
{//nSplitter的缺省值为5 wT `a3Ymm
//default value of nSplitter is 5 Q7R~{5r>W
this("","","",5); ZT,B(#m
} T? tG~
])L A42|
'`eO\huf
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KMU4n-s"o
{ I2 j}Am
sSiteURL= sURL; 4G$|Rx[{,
sFilePath = sPath; l7W 6qNB
sFileName = sName; <1FC%f/
this.nSplitter = nSpiltter; E0u~i59Z
&GlwC%$S
5!l0zLQPo
} _{r=.W+w
@c<3b2
LUuZ9$t0J"
public String getSSiteURL() 6xWe=QGE
{ ANJ$'3tg
return sSiteURL; >iD )eB
} : y5<go8e
wW#}:59}
Hj:r[/
public void setSSiteURL(String value) oN{Z+T :
{ I 4,K43|
sSiteURL = value; 2C/$Ei^t
} /h*>P:i].
P^w#S
Z2TL#@
public String getSFilePath() kB'Fkqwm
{ Eve.QAl|
return sFilePath; mMb'@
} "kMguK}c
3H|_mX
W6"v)Jc>_
public void setSFilePath(String value) cgm81+[%r
{ Fb7#<h
sFilePath = value; SILQ
} c3:,Ab|
UVw~8o9s
ag*mG*Z
public String getSFileName() :cq9f2)
{ 0TGLM#{
return sFileName; ^1Zeb$Nw'
} } p&&_?
4W3\P9p=
.a._NW
public void setSFileName(String value) \RvvHty-V
{ jFA{+Yr1
sFileName = value; 7N:Y?Hi\
} po$ /7
O [i#9)
xER\ZpA:,
public int getNSplitter() rb1`UG"h$
{ >TQH|}|6(y
return nSplitter; +m8!U=Zi
} ))&;}2{
m|=H#
q{t*34R
public void setNSplitter(int nCount) NX|v=
{ ,`gl&iB
nSplitter = nCount; d/bEt&
} mnmP<<8C,
} =$nB/K,8AX
H&]gOs3So
yil[gPy4B
/* M#~Cc~oT
**Utility.java w:?oTuw
*/ :,J}z~I,lB
package NetFox; XLL/4)
|!"2fI
Iz ;G*W18
public class Utility { Yc,7tUz#
O2BW6Wc
91$]Qg,lB
public Utility() %,Ap7X3:QT
{ :{oZ~<
~-PjW#J%
df n9!h
} Q8DQlqHm
;_^fk&+
//线程睡眠 0#ClWynjRO
public static void sleep(int nSecond) Eh|]i;G%
{ G.(mp<-
try{ |7X:TfJ
Thread.sleep(nSecond); `;)\u
} ik!..9aB
catch(Exception e) " t7M3i_
{ LxpuhvIO
e.printStackTrace (); 7oq[38zB
} >lBD<;T
} (HSgEs1d
g_G6~-.9I
//日志 x-?{E
public static void log(String sMsg) nzmDA6d
{ jcI&w#re
System.err.println(sMsg); YhY:~
} ds&e|VSH;
]ut5S>,"
$ZNu+tn Y
public static void log(int sMsg) $dA-2e10
{ 4"xPr[=iG
System.err.println(sMsg); cCa|YW^j
} NcP.;u;`
} {;.T7dL
2D:fJ~|-[
S-YM%8A[
/* |]aE<`D
**TestMethod.java KyzFnVH3)
*/ ~_s{0g]B
package NetFox; HW7; {QMg
*X4PM\ck
jq+A-T}@
public class TestMethod { $d,0=Ci
lhtZaU~V
c wOJy>
public TestMethod() $*kxTiG!7
{ ///xx/weblogic60b2_win.exe 6<$Odd
try{ ND5`Q"k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1&P<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Dgx8\~(E'
SiteFileFetch fileFetch = new SiteFileFetch(bean); J]q%gcM
fileFetch.start(); 8,atX+tc
} #?XQ7Im
catch(Exception e){e.printStackTrace ();} (XXheC
P9S2?Q
|QMhMGjV
} V=lfl1Ev0J
I8QjKI (
l983vKr
public static void main(String[] args) %/>Y/!;
{ 9JWa$iBH@
new TestMethod(); Rcawc Y
} JXw^/Y$
} ~j-cS J3
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