http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); PP'5ANK
} M=;csazN
for(int i=0;i<nEndPos.length-1;i++) G5t7KI
{ %_Lz0L64k
nEndPos = nStartPos[i+1]; dS 4/spNq
} FN!?o:|(
nEndPos[nEndPos.length-1] = nFileLength; _(' @'r
} .@nfqv7{
} jJ<&!=
LA\3 ,Uv
V(ww F
//启动子线程 ti9e(Jt!O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Sft vN-
for(int i=0;i<nStartPos.length;i++) |-\anby<
{ $=E4pb4Y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mMZ{W+"[f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F{ vT^/
nStartPos,nEndPos,i); ZR3,dW6S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8h|}Q_
fileSplitterFetch.start(); sRcd{)|Cq
} y,&[OrCm^\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 420K6[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vD9.X}l]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6o6yx:
nEndPos = " + nFileLength); |/l] ]+
// fileSplitterFetch[nPos.length-1].start(); By7lSbj
{N{eOa<HA
_7:Bxx4B
//等待子线程结束 *: FS/ir
//int count = 0; h~ _i::vg
//是否结束while循环 l{8O'4;
boolean breakWhile = false; g]z k`R5
Q!IqvmO
@(6i 1Iwu9
while(!bStop) a6z0p%sIZ
{ ,R-k]^O
write_nPos(); wVf 7<@/y
Utility.sleep(500); mk~CE
breakWhile = true; |-/@3gPO
R-ek O7z
Fng
for(int i=0;i<nStartPos.length;i++) -WyB2$!(
{ Y+23 jlgb
if(!fileSplitterFetch.bDownOver) ;2g.X(Ra
{ sXPva@8_
breakWhile = false; R>:D&$[RD
break; C "@>NC_
} RZpjr !R
} R{A$|Ipaq
if(breakWhile) JleClB(2n/
break; qrw*?6mSQ
T^7}Qs9
'Bt!X^
//count++; NkGtZ.!pk
//if(count>4) N6_1iIM
// siteStop(); )eZuG S
} *!`&+w
X{!,j}
v.:Q& ]
System.err.println("文件下载结束！"); (HeSL),1
} Pr%KcR ;
catch(Exception e){e.printStackTrace ();} 'M?ptu?f
} "-Nyf
v4rO 0y=C
8kU(>' ^_:
//获得文件长度 q*4@d)_&
public long getFileSize() #huh!Mn
{ p%bMfi*T
int nFileLength = -1; 1 <T|
try{ TK'y-5W
URL url = new URL(siteInfoBean.getSSiteURL()); IpzU=+h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dly -mPmP
httpConnection.setRequestProperty("User-Agent","NetFox"); mz<,nR\
XHgW9;M!
a|t{1]^w`
int responseCode=httpConnection.getResponseCode(); N|)e {|k
if(responseCode>=400) s-SFu
{ Z)(#D($-
processErrorCode(responseCode); 0;`FS/[(f
return -2; //-2 represent access is error fYZd:3VdC
} yNwSiZE X
UjJ&P)
5'{QMnfB
String sHeader; L)7{_s
#>~A-k)
Q8l vwip
for(int i=1;;i++) gxI/MD~!>
{ ?@MY+r_G
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); M54czo=l
//Utility.log(in.readLine()); ZK2&l8
sHeader=httpConnection.getHeaderFieldKey(i); L*6<h
if(sHeader!=null) 5HbJE'
{ +B+cN[d
if(sHeader.equals("Content-Length")) zJ1M$U
{ c@]G;>o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D2o|.e<r
break; ^a3 (QKS
} r_bG+iw7p
} 7bGt'gvv
else bqF?!t<B
break; 4C:dkaDq]
} OOnj(%g
} 0?I
catch(IOException e){e.printStackTrace ();} ~tW<]l7
catch(Exception e){e.printStackTrace ();} 3_ E}XQd
Ya<KMBi3
q]!FFi{w;
Utility.log(nFileLength); X>yE<ni
{~g7&+9x*
Z!'kN\z
return nFileLength; 2.{<C.BK{
} =7:}/&
hlc g[Qdo*
fyx Q{J
//保存下载信息（文件指针位置） W S9:*YH
private void write_nPos() =/ !A
{ 0@u{(m
try{ p!Tac%D+k
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4>Q] \\Lc
output.writeInt(nStartPos.length); jt3W.^6HO
for(int i=0;i<nStartPos.length;i++) $'#}f?
{ 3|3ad'
// output.writeLong(nPos); B<@a&QBTg
output.writeLong(fileSplitterFetch.nStartPos); w+\RSqz/
output.writeLong(fileSplitterFetch.nEndPos); R[vX+d!7
} v=uQ8_0~N
output.close(); =:xJZy$
} =3V4HQi
catch(IOException e){e.printStackTrace ();} wt_ae|hv
catch(Exception e){e.printStackTrace ();} {JKG-0)z?
} 3_eg'EP.E
f e^s`dsG
b*nI0/cbR.
//读取保存的下载信息（文件指针位置） kY4h-oZ
private void read_nPos() l`j@QP
{ >E,/|K*
try{ ^ 6t"A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .rDao]K
int nCount = input.readInt(); 8|hi2Qeu,c
nStartPos = new long[nCount]; b3GTsX\2|
nEndPos = new long[nCount]; 6is+\
for(int i=0;i<nStartPos.length;i++) rg%m
{ 3],(oQq^
nStartPos = input.readLong(); yM-%x1r~
nEndPos = input.readLong(); ecp0 hG`%
} ;gRPTk$X3
input.close(); |NjyO>@Pa
} hSh^A5 /
catch(IOException e){e.printStackTrace ();} #fyY37-
catch(Exception e){e.printStackTrace ();} cIuCuh0I`
} * _,yK-et
dftX$TS
73nmDZO|
private void processErrorCode(int nErrorCode) dW^#}kN7V
{ RD:LNl<0sh
System.err.println("Error Code : " + nErrorCode); = j l(Q
} IeIv k55
+fMW B
Jx4~o{Z}c
//停止文件下载 4tapQgj24
public void siteStop() diw5h};W
{ B,4GxoX`
bStop = true; FQMA0"(G$
for(int i=0;i<nStartPos.length;i++) o3OJI_ v&
fileSplitterFetch.splitterStop(); L{c\7
~;wR}s<}(
KZ [:o,jp>
} }L5;=A']S
} MF::At[4
//负责部分文件的抓取 kw1Lm1C
**FileSplitterFetch.java LyNur8 Zi
*/ !<>`G0
package NetFox; qMBEJ<o
@c,=c+-
@oMl^UYM=
import java.io.*; /-3)^R2H
import java.net.*; .Ag)/Xm(?
-dUXd<=ue
lWU? R
public class FileSplitterFetch extends Thread { &G+:t)|S
2|+4xqNJm
kr]_?B(r
String sURL; //File URL 3SOrM
long nStartPos; //File Snippet Start Position x C>>K6Nb
long nEndPos; //File Snippet End Position )q%DRLD'G
int nThreadID; //Thread's ID @hOY&
boolean bDownOver = false; //Downing is over hN1{?PQ
boolean bStop = false; //Stop identical j0e1CSE
FileAccessI fileAccessI = null; //File Access interface K5d>{c
xkz`is77Y@
t\<*Q3rl-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o6:p2W
{ d8f S79
this.sURL = sURL; 4wwRNu*
this.nStartPos = nStart; !z?:Y#P3
this.nEndPos = nEnd; LoS%FI
nThreadID = id; b=Q%Jxz?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @,q<][q
} 9kU|?JE
js=w!q0)9
*>Zq79TG
public void run() XZPq4(,9}
{ <ZeZq
while(nStartPos < nEndPos && !bStop) <$'FTv
{ 0OVxx>p/x
HG})VPBa
mz .uK2l{
try{ ob=IaZ@?
URL url = new URL(sURL); X]%n#\t,]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }Q>??~mVl
httpConnection.setRequestProperty("User-Agent","NetFox"); 3ry0.
String sProperty = "bytes="+nStartPos+"-"; ,tOc+3Qz$
httpConnection.setRequestProperty("RANGE",sProperty); q?Mmkh)g
Utility.log(sProperty); If.hA}
Ob7F39):N
e5cvmUF_W
InputStream input = httpConnection.getInputStream(); /=:X,^"P
//logResponseHead(httpConnection); a 1pa#WC
}Xy<F?Mh
N6S}u@{J~N
byte[] b = new byte[1024]; ;KW}F|
int nRead; ?$X1X`@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) QPwUW
{ H52] Zm
nStartPos += fileAccessI.write(b,0,nRead); 3sBu`R*hk
//if(nThreadID == 1) ;z^C\=om
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >1d`G%KfG
} ,7|2K&C5
nSV OS6
}o#6g|"\sY
Utility.log("Thread " + nThreadID + " is over!"); / CVhvK
bDownOver = true; Z6r_T
//nPos = fileAccessI.write (b,0,nRead); =wX(a
} W-@}q}A
catch(Exception e){e.printStackTrace ();} mmgIV&P
} Gcu?xG{
} 1'[_J
tdB<
5i1Xumh 4
//打印回应的头信息 ZZ{:f+=?$
public void logResponseHead(HttpURLConnection con) }Z}4_/E
{ |B.tBt^
for(int i=1;;i++) '>5W`lZ
{ $[8GFv
String header=con.getHeaderFieldKey(i); c4n]#((%a
if(header!=null) ?i7}d@636
//responseHeaders.put(header,httpConnection.getHeaderField(header)); YXhxzH hPd
Utility.log(header+" : "+con.getHeaderField(header)); keWqL]
else iOzY8M+N(
break; L+y90 T6?
} Ce1^S[
} yGtGhP8
=;^#5dpt$
ue{0X\[P<
public void splitterStop() r%~/y
{ (Y%pk76d
bStop = true; re\&'%~K
} Vi1= E])
E"$AOM?(*i
Y5Jrkr)k
} 7nAB^~)6l
Z-,'M tD
k~ZE4^dM
/* 9.qjEe
**FileAccess.java H[&X${ap
*//文件访问(定位，写) vEIDf{
package NetFox; IH1 fvW e
import java.io.*; H$i4OQ2
U6@j=|q
`-L{J0xq
public class FileAccessI implements Serializable{ VCZ.{MD
0WI3m2i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RZV6\j
RandomAccessFile oSavedFile; PYp<eo\
long nPos; TS{ycGY
*CtOQ
EpCsJ08K
public FileAccessI() throws IOException ..xg4V/
{ &k4)&LQJ
this("",0); Ec^x
} B&E qd
~ g\GC
Gn_rf"
public FileAccessI(String sName,long nPos) throws IOException {@c)!%2$
{ xi2!__
oSavedFile = new RandomAccessFile(sName,"rw"); jKI0d+U
this.nPos = nPos; B2PjS1z2
oSavedFile.seek(nPos); HG/`5$L +}
} S~mpXH@
)ieT/0nt
W7QcDR y6
public synchronized int write(byte[] b,int nStart,int nLen) 2Po e-=
{ " E U[Lb
int n = -1; 2.zx
try{ QFm~wv8:
oSavedFile.write(b,nStart,nLen); q;p:)Q"
n = nLen; VnB"0"%w
} b]Xc5Dp{
catch(IOException e) ,dM}B-
{ ,Mp/Y>f
e.printStackTrace (); &nk[gb o\
} @3hA\3ot^
pPNU0]/
Q^qdm5}UkW
return n; R7)2@;i
} &xG>"sJ
i+)9ItZr
Bu\:+3)
} +&7D ;wj=
k%5o5Hx
O.%' 47A
/* `czL$tN<P
**SiteInfoBean.java cZ{-h
*/ M}]E,[
package NetFox; 4#oLf1
B=mk@gX,G
*TEgV
public class SiteInfoBean { n-P)X<\
#G;0yB:76
J1Ay^*qRU
private String sSiteURL; //Site's URL ?n 9<PMo
private String sFilePath; //Saved File's Path yaiw|j`A
private String sFileName; //Saved File's Name M~Tx4_t
private int nSplitter; //Count of Splited Downloading File t<Iy`r71
F|t3%dpj
}6;v`1Hr
public SiteInfoBean() y Q_lJIX
{//nSplitter的缺省值为5 -^i[
//default value of nSplitter is 5 IXaF(2>
this("","","",5); MY]Z@
} a&3pPfC
dVh* a
Gy+/P6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Gf(|?" H
{ iB =R
sSiteURL= sURL; '+6SkZ
sFilePath = sPath; p_x@FA(
sFileName = sName; nwOT%@nw
this.nSplitter = nSpiltter; Lc<v4Bp
@pcmVsIp
|#p`mc%f~\
} `@$qy&AJ
+=v6*%y"V
)*=ds,
public String getSSiteURL() .</`#
{ w%(Ats
return sSiteURL; 0=3Av8
} 5E|y5|8fb
2UPqn#.3
MCBZq\c
public void setSSiteURL(String value) o(=\FNe
{ %s}c#n)N
sSiteURL = value; ]m _<lRye
} 8[zux4<m
8<gYB$* S
:T62_cFG
public String getSFilePath() ?pS,?>J f
{ sEQAC9M
return sFilePath; #bz#&vt$
} zJhG`iWFw
\uT2)X( N
a^U)2{A*f
public void setSFilePath(String value) U}w,$ Y
{ +K6j p
sFilePath = value; r5h+_&v,M
} 5%+M:B
hG~TqH^}B
gLyXe,Jp
public String getSFileName() `1AVw]k
{ oa4{s&db-
return sFileName; PBXRey7>D
} yfq Vx$YL
Pz+2(Z
sop*?0
public void setSFileName(String value) UMcQqV+vT
{ 8F?6Aq1B
sFileName = value; F/91Es
} l[Hgh,
~N<zv({lG
5crd.1@^
public int getNSplitter() 2U;6sn*e
{ _"b[UT}m
return nSplitter; KaEL*
} cPFs K*w
fl8~*\;Xu
M0+xl+c+
public void setNSplitter(int nCount) 4f)B@A-
{ g4Y1*`}2f
nSplitter = nCount; b4Y<
} 4=BIYC"Lu
} 3PmM+}j3
#@rvoi
_,,w>q6K
/* ZDQc_{e{
**Utility.java |"j{!Ei
*/ S.u1[Yz^
package NetFox; s7"NK"
]Alv5?E60
iJ&*H)}^
public class Utility { ku8C#%.m3
UDBMf2F]
MBeubS
public Utility() Wu}84W"!.V
{ 16J"QUuG
'AU:[eyUV
%5?Zjp+9
} /0.m|Th'm
thT2U8%T
//线程睡眠 8h,>f#)0c
public static void sleep(int nSecond) 8-s7^*!
{ GkOZ=ej
try{ &xAwk-{W
Thread.sleep(nSecond); T[M:%vjYF
} VLdQXNg9W"
catch(Exception e) y.iA]Ikz
{ wFe?0u
e.printStackTrace (); @%aU)YDwi
} Q%_QT0H9Kz
} ^x BQ#p
#N?VbDK9_
//日志 ;hz;|\ko5
public static void log(String sMsg) mz[Q]e~&i
{ {5GXN!f
System.err.println(sMsg); -:$#koW
} >cTSX
C2X$bX"
bfE4.YF
public static void log(int sMsg) {*BZ;Xh\8
{ 3xhGmD\SKO
System.err.println(sMsg); nM<B{AR5^
} IBT1If3
} R[qfG! "
Lrrc&;
Y8%bk2
/* PLb[U(~
**TestMethod.java j[ fE^&
*/ y7X2|$9z-
package NetFox; H(A9YxXrZ5
m@,u&9K
;4MC/Q/
public class TestMethod { ^MXW,xqb
3i*HwEh
c:d.mkF\
public TestMethod() e+TSjm
{ ///xx/weblogic60b2_win.exe <n;9IU
try{ !l(O$T9T
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "mtEjK5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); rk E;OU
SiteFileFetch fileFetch = new SiteFileFetch(bean); iAl.(j
fileFetch.start(); j;7:aM"BQW
} N6>ert1
catch(Exception e){e.printStackTrace ();} xlP0?Y1Bl
hFQ*50n}
(:9=M5d
} vWs#4JoG
{%&!x;%
59@PY!c>
public static void main(String[] args) S/2lK*F
{ _+aMP=H
new TestMethod(); 1(diG&
} Q?g#?z&Pu\
} +$;#bw)yH
点击下载更多相关资料