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)); .0a$E`V=D
} #a .aD+d'
for(int i=0;i<nEndPos.length-1;i++) #vDe/o+=
{ a(J~:wgd
nEndPos = nStartPos[i+1]; oa9T3gQ?
} \7/xb{z|
nEndPos[nEndPos.length-1] = nFileLength; DAvAozM
} .d8~]@U!<
} }RyYzm2
sF<4uy
](a<b@p
//启动子线程 I`y}Ky<q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; FijzO
for(int i=0;i<nStartPos.length;i++) -AffKo
{ XDI@mQmzB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FvvF4 ,e5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `Zk?.1*2/
nStartPos,nEndPos,i); c^=,@#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Pd@?(WQ
fileSplitterFetch.start(); ^$T>3@rDB
} 1= <Qnmw
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9^aMmN&6N2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :_?>3c}L
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GJ((eAS)
nEndPos = " + nFileLength); +Uk/Zg w^
// fileSplitterFetch[nPos.length-1].start(); "urQUpF
tZ6KU11O
H~$a6T"&
//等待子线程结束 XGO_n{x
//int count = 0; w>!KUT
//是否结束while循环 .IYE"0)wJ
boolean breakWhile = false; :|fzGf
QzV:^!0J
|9(uiWf
while(!bStop) 4W1"=VL[g
{ Tlf G"HzZ%
write_nPos(); W{0<ro`
Utility.sleep(500); p oNQ<ijK
breakWhile = true; l$zM|Z1wR`
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g@S"!9[;U
for(int i=0;i<nStartPos.length;i++) G_X'd
{ hx:x5L>
if(!fileSplitterFetch.bDownOver) ^c-1wV`/
{ K\;b3
breakWhile = false; IJs`3?
break; 0_%u(?
} BGUP-_&
} Dpof~o,f
if(breakWhile) T"dEa-O
break; paiF ah
km8[azB o
+='.uc_
//count++; j[c|np4k\
//if(count>4) SFh6'v'1N@
// siteStop(); Z,Q)\W<'-
} R[Pyrs!H
q,+d\-+
Mb+cXdZb
System.err.println("文件下载结束！"); Blf;_e~=[j
} ^Dd$8$?[
catch(Exception e){e.printStackTrace ();} mF#{"
} ~xzRx$vU
6{1c S
<G#JPt6
//获得文件长度 eyUo67'7
public long getFileSize() N|8TE7- F|
{ jtN2%w;
int nFileLength = -1; 4GaF:/
try{ `F(KM '
URL url = new URL(siteInfoBean.getSSiteURL()); s_VP(Fe@K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e>MC 3D`5
httpConnection.setRequestProperty("User-Agent","NetFox"); rbs:qLa%
h*&-[nSo
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int responseCode=httpConnection.getResponseCode(); K~C*4H:9
if(responseCode>=400) dRt]9gIsx
{ }cMb0`oA
processErrorCode(responseCode); Rl-Sr
return -2; //-2 represent access is error /1g_Uv;
} ,LU/xI0O
RXLD5$s^
NCd_h<}|6F
String sHeader; mVW:]|!s
%5a>@K]
K^w(WE;db
for(int i=1;;i++) YW0UIO
{ |WlWZ8]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^qYJx
//Utility.log(in.readLine()); !SEg4z
sHeader=httpConnection.getHeaderFieldKey(i); k6.}.
if(sHeader!=null) pT.iQ J|
{ gHA"O@HgDI
if(sHeader.equals("Content-Length")) "ifYy>d
{ @)|62Dv /
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |%we@ E
break; r#3(;N{=
} =K}5 fe
} \h?C G_|]
else yw$er?
break; }M * Oo
} &+d>xy\^/
} ojUBa/
catch(IOException e){e.printStackTrace ();} j:\MrYt0H
catch(Exception e){e.printStackTrace ();} i\2~yXw\
Z6A*9m
"\)j=MI8u+
Utility.log(nFileLength); &8z`]mB{t
n<uF9N<
4tof[n3us
return nFileLength; z45ImItH
} q:+,'&<D
$62!R]C9\
O}"VK
//保存下载信息（文件指针位置） pQ!NhzQ
private void write_nPos() [n44;
{ M)#aX|%Mh
try{ -]\UFR
output = new DataOutputStream(new FileOutputStream(tmpFile)); v:nm#P%P
output.writeInt(nStartPos.length); ^ ,d!K2`
for(int i=0;i<nStartPos.length;i++) 8:|F'{<<b
{ #\_N-bVu
// output.writeLong(nPos); a4Fe MCvV9
output.writeLong(fileSplitterFetch.nStartPos); S{7A3 x'B
output.writeLong(fileSplitterFetch.nEndPos); k$j>_U? P
} HSE9-c=
output.close(); {+F/lN@
} bM;==W
catch(IOException e){e.printStackTrace ();} -uHD| }
catch(Exception e){e.printStackTrace ();} @~qlSU&
} n&jfJgD&g
*?VbN}g2
DKx8<yEky
//读取保存的下载信息（文件指针位置） py6|uGN
private void read_nPos() =rMT1
{ nm_]2z O
try{ $0~H~-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); s=h
int nCount = input.readInt(); ?4P*,c
nStartPos = new long[nCount]; ryg1o=1v/
nEndPos = new long[nCount]; bx_`S#*N
for(int i=0;i<nStartPos.length;i++) z:{'IY
{ waz)jEk
nStartPos = input.readLong(); Zui2O-L?V
nEndPos = input.readLong(); w$MFCJ:p&
} NTkGLD1e.
input.close(); 4p\<b8(9>
} oJA%t-&%R
catch(IOException e){e.printStackTrace ();} PbvRh~n
catch(Exception e){e.printStackTrace ();} iC10|0%{
} ~Pq1@N>n
FctqE/>}I
oi^2Pvauh
private void processErrorCode(int nErrorCode) 33z)F
{ wC+_S*M-K
System.err.println("Error Code : " + nErrorCode); $6kVhE!;
} $vlq]6V8
BT.;l I
\09eH[
//停止文件下载 _~ZNX+4
public void siteStop() rXPq'k'h#-
{ w7@fiH{
bStop = true; 3(0k!o0"
for(int i=0;i<nStartPos.length;i++) ze@NqCF
fileSplitterFetch.splitterStop(); (A|Gb2X
@KfFtR-;
D~E1hr&Vd>
} a|Io)Qhr
} eKPxSN Z
//负责部分文件的抓取 h,o/(GNnW
**FileSplitterFetch.java j6]+fo&3
*/ +P:xB0Tm D
package NetFox; YBqu7&
uLX5khQ
l=,\ h&
import java.io.*; e33j&:O
import java.net.*; >qk[/\^O
#Mkwd5S|L
,:Qy%k}f
public class FileSplitterFetch extends Thread { Fa:fBs{
h U\)CM
{>PN}fk2QP
String sURL; //File URL 6A&e2K>A
long nStartPos; //File Snippet Start Position KJ M:-z@
long nEndPos; //File Snippet End Position ufyqfID
int nThreadID; //Thread's ID Dvbrpn!sk
boolean bDownOver = false; //Downing is over q1}HsTnBH
boolean bStop = false; //Stop identical g`I`q3EF)
FileAccessI fileAccessI = null; //File Access interface yV[9 (
"Ah (EZAR
l$N b1&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #-*7<wN
{ sLrSi
this.sURL = sURL; Z M_ 6A1
this.nStartPos = nStart; ywWF+kR_
this.nEndPos = nEnd; RZ 4xR
nThreadID = id; {G$I|<MD2T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zO8`xrN!
} K(@QKRZ7[
g S xK9P
d*Q:[RUf,
public void run() itClCEOA
{ (WZKqt)S"o
while(nStartPos < nEndPos && !bStop) 0goKiPx
{ "h?;)Ye
RP 'VEJ
:ZG^`H/X1d
try{ 6$c,#%Jt*
URL url = new URL(sURL); 7ADh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e&%m[:W:<
httpConnection.setRequestProperty("User-Agent","NetFox"); `2`Nu:r^
String sProperty = "bytes="+nStartPos+"-"; WwG +Xa
httpConnection.setRequestProperty("RANGE",sProperty); jR-DH]@y
Utility.log(sProperty); &S[tI$
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J%}9"Q5
InputStream input = httpConnection.getInputStream(); g-lF{Z
//logResponseHead(httpConnection); 5y-8_)y8o
AKs=2N>7
."b=dkx
byte[] b = new byte[1024]; $Lg%CY
int nRead; %{qJkjG
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dayp1%d
{ 6QS[mWU
nStartPos += fileAccessI.write(b,0,nRead); m| 8%%E}d
//if(nThreadID == 1) $Gt1T[:QUX
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D>"U0*h
} }%LwaRT
`~|8eKFq!
pgT XyAP{
Utility.log("Thread " + nThreadID + " is over!"); . +_IpygQ
bDownOver = true; GtI]6t
//nPos = fileAccessI.write (b,0,nRead); j$r.&,m
} B198_T!
catch(Exception e){e.printStackTrace ();} +bK[3KG4F5
} f5D.wSY
} KY'"Mg^!
18JhC*in
0_b7*\xc
//打印回应的头信息 ;4.D%
public void logResponseHead(HttpURLConnection con) <K4`GT"n
{ rx`G*k{X
for(int i=1;;i++) L-ans2?
{ K8E:8`_cx
String header=con.getHeaderFieldKey(i); ~@a7RiE@
if(header!=null) @?ntMh6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); E-h`lDoJ
Utility.log(header+" : "+con.getHeaderField(header)); VesW7m*z
else 2y; |6`
break; o%#Z
} K0B J
} N}{CL(xi
/E>z8J$
,Nl]rmI
public void splitterStop() aIaydu+\
{ !R,9Pg*Ey
bStop = true; J]uYXsC
} 9D74/3b*
^aVoH/q*C
'G z>X :
} %-"?
<}'hkEh{d=
pKK&+umg
/* 3$f%{~3
**FileAccess.java INwc@XB
*//文件访问(定位，写) cyUNJw
package NetFox; $4.mRS97g
import java.io.*; 4eb<SNi
JtYc'%OF
EFeG[bxM
public class FileAccessI implements Serializable{ !NuYx9L?L
-x )(2|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 pGw|T~e%
RandomAccessFile oSavedFile; TnET1$@qr*
long nPos; YLk; ^?
Mi'Q5m
lh`inAt)"
public FileAccessI() throws IOException A(AyLxB47*
{ n0:+D R
this("",0); Zrfp4SlZZ
} $hB;r
2=tPxO')B
Cnf;5/
public FileAccessI(String sName,long nPos) throws IOException 2D-ogSIo
{ qg#WDx /
oSavedFile = new RandomAccessFile(sName,"rw"); Bv"Fx*{W
this.nPos = nPos; WH :+HNl1d
oSavedFile.seek(nPos); L;.6j*E*
} 'qLk"
j9C=m"O
5n;|K]UW
public synchronized int write(byte[] b,int nStart,int nLen) Avw"[~Xd
{ 9[5NnRv$P
int n = -1; 2YK4SL
try{ n`f},.NM|
oSavedFile.write(b,nStart,nLen); s%]-Sw9
n = nLen; z.23i^Q
} }|f\'S
catch(IOException e) $I_04k#t
{ ]!H*oP8a*
e.printStackTrace (); >VP\@xt(R[
} #V-qS/ q"
9,5v%HZ
ri~dWx
return n; wbI(o4rXE
} Y%qhgzz?/
sBp|Lo
pfg"6P
} _J&u{
rPK?pJ
GN{\ccej
/* )<4o"R:*
**SiteInfoBean.java W"Dj+/uS
*/ 9.e?<u*-z
package NetFox; n]4)~ZIAU
Rz`<E97-
93fKv
public class SiteInfoBean { `u:U{m
#c4LdZu9
;3\Fb3d
private String sSiteURL; //Site's URL Szi4M&!K
private String sFilePath; //Saved File's Path (d993~|h
private String sFileName; //Saved File's Name tZ>>aiI3
private int nSplitter; //Count of Splited Downloading File u]E%R&
@&+h3dV.V
?t)y/@eG
public SiteInfoBean() 7|zt'.56[
{//nSplitter的缺省值为5 `]]gD EPG{
//default value of nSplitter is 5 ]Vjn7P`~N
this("","","",5); #f.@XIt'
} nL^6{I~
f&`v-kiAn=
)Tngtt D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9 N=KU
{ [gzU/:
sSiteURL= sURL; UE7P =B
sFilePath = sPath; D]y6*Ha
sFileName = sName; }3:TPW5S
this.nSplitter = nSpiltter; psRm*,*O
y5a^xRDw
EN.yU!N.4
} lGG1d
w,8 M
] >ipC,v
public String getSSiteURL() sLbz@54
{ toTAWT D
return sSiteURL; /dOQ4VA\
} =i%2/kdi0b
PyYKeo=
0x^$q? \A
public void setSSiteURL(String value) pY=?r{@
{ spO?5#
sSiteURL = value; o~P8=1t
} b{sE#m%r
1:YDN.*
s>~&:GUwR
public String getSFilePath() i04Sf^
{ Si]Z`_
return sFilePath; 4)Pt]#Ti
} 8SAz,m!W)
q*{"6"4(
UMhM8m!=o
public void setSFilePath(String value) w?M*n<) O
{ +\Q6Onqr
sFilePath = value; .E;6Xx_+r
} od^ha
jn}6yXB
}r^MXv~(
public String getSFileName() I]SR.Yp%
{ vA`[#(C
return sFileName; 5@[%P=
} }sJ%InL
0SKt8pL`
;t?pyFT2Z
public void setSFileName(String value) Ur&: Rr
{ 8QC:ro
sFileName = value; iT^lk'?{O
} P#ru-0DD
-m'a%aog
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public int getNSplitter() w4L\@y3
{ ^;@Bz~Z
return nSplitter; '3hvR4P
} ^* DKF
H8\{GGg
u]dpA
public void setNSplitter(int nCount) Ds}6{']K
{ A5H[g`&
nSplitter = nCount; RuRJjcnY
} N,[M8n,
} ?J6hiQvL
:He:Bdk
/=r&9P@Ay<
/* \17)=W
**Utility.java n.1a1Tf
*/ &R^mpV5
package NetFox; _R-#I
HKxrBQr78
LoCxoAg
public class Utility { "R9kF-
H`io|~Q
fZ %ZV
public Utility() {?L}qV
{ JK_$A;Q
&P+cTN9)
4P:vo$Cy
} Sr+1.77}
R>0ta Q
//线程睡眠 ?1412Tq5
public static void sleep(int nSecond) +M.|D,wg2
{ rW6w1
try{ *v5y]E%aW
Thread.sleep(nSecond); a9qZI
} g)p[A 4
catch(Exception e) %##9.Xm6l
{ cxv)LOl-
e.printStackTrace (); Hd2_Cg FB
} s~63JDy"E
} 5rcno.~QO
(6A{6_p
//日志 rpXw 8
public static void log(String sMsg) rvfl~<G*
{ Z'j<wRf
System.err.println(sMsg); *l9Y]hinq
} d*AV(g#B
1)Ag|4
q;AQ6k(
public static void log(int sMsg) ?41| e+p
{ >qgBu_
System.err.println(sMsg); )eG&"3kFe!
} oDP|>yXC)
} }`g*pp*
Anm5Cvt;i
^IId =V=2
/* 3&*%>)
**TestMethod.java Rd!.8K[
*/ n&Tv]-
package NetFox; .ev]tu2N
[{c8:)ar
[a Z)*L ;
public class TestMethod { M1>a,va8Zq
"bO]
vaU7tJ:
public TestMethod() +I~?8*
{ ///xx/weblogic60b2_win.exe rLXn35O
try{ u}h'v&"e,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aOuon0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W>Kwl*Cis"
SiteFileFetch fileFetch = new SiteFileFetch(bean); *>#cs#)
fileFetch.start(); x$p\ocA
} J+4uUf/d!
catch(Exception e){e.printStackTrace ();} Q:LuRE!t
Umd!j,
S:j0&*
} *Xo f;)Z^
";xEuX
Ay`a>:p
public static void main(String[] args) <wA_2S Y
{ d^Wh-U
new TestMethod(); bpILiC
} N?Z?g_a8
} !6%mt}h
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