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)); =o5|W'>`
} S0' ACt`
for(int i=0;i<nEndPos.length-1;i++) S aH':UN
{ "}x%5/(
nEndPos = nStartPos[i+1]; 2;w`W58
} `x]`<kS;
nEndPos[nEndPos.length-1] = nFileLength; 7C9_;81_Dt
} /os,s[w
} }3}H}
zMXQfR
|[Rlg`TQ;*
//启动子线程 y}U}AUt
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sR4B/1'E
for(int i=0;i<nStartPos.length;i++) (2ZkfN
{ l86gs6>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DS1{~_>nFu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]SmN}Iq1
nStartPos,nEndPos,i); ictV7)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `k6ZAOQtX
fileSplitterFetch.start(); f.Y [2b
} TjE'X2/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,rS?^"h9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); I<rT\':9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )~0TGy|
nEndPos = " + nFileLength); mKBO<l{S
// fileSplitterFetch[nPos.length-1].start(); b+CJRB1
VTa%
5HaI$>h6
//等待子线程结束 c;Gf$9?iC
//int count = 0; SJ2l6
//是否结束while循环 al"=ld(
boolean breakWhile = false; L++qMRk9
[jv+Of IZ
kMx)G]
while(!bStop) ;pw9+zo^M
{ zP&D
write_nPos(); tv_&PIu]L
Utility.sleep(500); bXi!_'z$
breakWhile = true; P~M[i9 V
1,(WS F
PX*}.L *x
for(int i=0;i<nStartPos.length;i++) 1\a.o[g3e
{ v5\5:b{/
if(!fileSplitterFetch.bDownOver) V}Ee1C
{ :,ucJ|
breakWhile = false; #g/m^8n?s
break; !z1\#|>
} nb.|^O?
} <aLS4
if(breakWhile) Q5b9q$L$
break; =4$ErwI_dm
%P7qA
|\W53,n9
//count++; r )HZaq
//if(count>4) /9=r.Vxh
// siteStop(); oY+p;&H
} N%?R(
_X|prIOb=
WvZt~x&2
System.err.println("文件下载结束！"); Z9.0#Jnu
} :(\JY?+w
catch(Exception e){e.printStackTrace ();} ?N(<w?Gat
} G c\^Kg^#
gyb99c,)
UiVGOQq
//获得文件长度 d_Jj&:"l
public long getFileSize() :dqZM#$d
{ Gj?$HFa
int nFileLength = -1; 6?Kl L [~
try{ inFS99DKx
URL url = new URL(siteInfoBean.getSSiteURL()); l/,la]!T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `^] D;RfE
httpConnection.setRequestProperty("User-Agent","NetFox"); @C<ofg3E
&)jq3
\1SC:gN*#
int responseCode=httpConnection.getResponseCode(); i),bAU!+m
if(responseCode>=400) 'J$@~P
{ 9GRQ^E
processErrorCode(responseCode); zn>+\
return -2; //-2 represent access is error wBvVY3VQ^
} ZS%W/.?
;{aGEOP'U
`U=Jbdc l3
String sHeader; Af\
Vm[F~2+HX
1Au+X3
for(int i=1;;i++) Xo:Mar
{ 2e-`V5{)b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); x0b=r!Duu
//Utility.log(in.readLine()); v$D U q+
sHeader=httpConnection.getHeaderFieldKey(i); x5CMP%}d
if(sHeader!=null) ?%[~J
{ 2n$Wey[
if(sHeader.equals("Content-Length")) peF)U !`D
{ 1yZA_x15:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *`rfD*
break; uIbAlE
} ZSs@9ej
} y%X!l(gQ
else 5|=J\Lp2I
break; x9AFN
} #%2d;V
} cS'{h
catch(IOException e){e.printStackTrace ();} zPxR=0|
catch(Exception e){e.printStackTrace ();} W7Y@]QMX
B;?)X&n|X
/y$Fw9R;
Utility.log(nFileLength); b*.aaOb
k qL.ZR
4g"%?xN
return nFileLength; 8]Tv1Wc
} ,~=]3qmbR
eZ+6U`^t
.>eRX%
//保存下载信息（文件指针位置） NhCucSU<K
private void write_nPos() lcm3wJ'w
{ E*u*LMm
try{ BvsSrse
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1f<R,>
output.writeInt(nStartPos.length); #G.eiqh$a
for(int i=0;i<nStartPos.length;i++) aopZ-^
{ +]nIr'V
// output.writeLong(nPos); MqB@}!
output.writeLong(fileSplitterFetch.nStartPos); +C8O"
output.writeLong(fileSplitterFetch.nEndPos); eb}P/
} *!ng)3#
output.close(); Ps>:|j+
} 9OV@z6
catch(IOException e){e.printStackTrace ();} $L8>Ha}
catch(Exception e){e.printStackTrace ();} rD~/]y)t
} 0cE9O9kE
0U@#&pUc
}L)[>
//读取保存的下载信息（文件指针位置） &hO-6(^I
private void read_nPos() ;aV3j/
{ L FkDb}
try{ vMB61 |O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); aZ4?!JW.
int nCount = input.readInt(); kqm(D#
nStartPos = new long[nCount]; Gk{ 'U
nEndPos = new long[nCount]; :Y\ ~[Y
for(int i=0;i<nStartPos.length;i++) **L&I5Hhm
{ S)rr
nStartPos = input.readLong(); 60vmjmXl
nEndPos = input.readLong(); \1jThJn
} jkx>o?s)z
input.close(); jel:oy|_
} Ig t*8px
catch(IOException e){e.printStackTrace ();} C[<}eD4bV
catch(Exception e){e.printStackTrace ();} <@"rI>=
} %*}rLn"?
Yr/$92(
Jgv Mx
private void processErrorCode(int nErrorCode) 7%i'F=LzT
{ hqvhnqQk
System.err.println("Error Code : " + nErrorCode); X7huc*
} $C;i}q#
}[;ZZm?
?E"192,z@
//停止文件下载 9L:wfg}8s
public void siteStop() 'EiCTl
{ L@{'J
bStop = true; qC> tni%
for(int i=0;i<nStartPos.length;i++) Vo@7G@7K(
fileSplitterFetch.splitterStop(); U-9Aq
X|T|iB,vT
!xfDWbvHV
} SjB"#E)
} \jwG*a
//负责部分文件的抓取 1H-Y3G>jN
**FileSplitterFetch.java a]u.Uqyx2w
*/ q4[}b-fF
package NetFox; UeO/<ml3>J
{&,p<5o
j|[rT^b@
import java.io.*; 9?H$0xZV
import java.net.*; ; R}>SS'
^)~Smj^d
Wp>t\S~N
public class FileSplitterFetch extends Thread { `FPQOa*%3
5G}4z>-]F)
}ouGxs+^[
String sURL; //File URL {&n- @$?
long nStartPos; //File Snippet Start Position ~i"=:D
long nEndPos; //File Snippet End Position F<,pAxl~@
int nThreadID; //Thread's ID 3p=Xv%xd
boolean bDownOver = false; //Downing is over E:x@O8F
boolean bStop = false; //Stop identical ks0Q+YW
FileAccessI fileAccessI = null; //File Access interface ?Fl}@EA#M
%=UD~5!G0
BA c+T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException KMj\A d
{ ->b5"{t
this.sURL = sURL; v`Jt+?I
this.nStartPos = nStart; wHj1+W
this.nEndPos = nEnd; 9 8|sWI3B
nThreadID = id; o1ZVEvp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jg710.v:
} tTy!o=
5v)^4( )
,%TBW,>
public void run() r >'tE7W9
{ o}v<~v(
while(nStartPos < nEndPos && !bStop) ~#sD2b`0
{ U3{<+vSR`
Z<i}XCE
v0\l~_|H
try{ {$z54nvw$
URL url = new URL(sURL); 1%+-}yo<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qSvV|G
httpConnection.setRequestProperty("User-Agent","NetFox"); :hZM$4
String sProperty = "bytes="+nStartPos+"-"; m !*F5x
httpConnection.setRequestProperty("RANGE",sProperty); BYq80Vk%@
Utility.log(sProperty); mKZzSd)p
}=/zG!+
@:}c(j
InputStream input = httpConnection.getInputStream(); y(J~:"}7)
//logResponseHead(httpConnection); ^/"}_bR
nqo{]fn
Op%OQ14$
byte[] b = new byte[1024]; xJCxzJ
int nRead; tP@NQCo
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i//H5D3
{ \ASt&'E
nStartPos += fileAccessI.write(b,0,nRead); SY+0~5E
//if(nThreadID == 1) fkZHy|m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g{Hgs
} Me.I>7c
s(=wG|
$X#y9<bW
Utility.log("Thread " + nThreadID + " is over!"); ^X96yj'?
bDownOver = true; |(.\J`_e
//nPos = fileAccessI.write (b,0,nRead); wb$uq/|
} `9^tuR,
catch(Exception e){e.printStackTrace ();} |{N{VK
} +K1M&(
} KR>)Ek
Iq+N0G<j
Pf[E..HF*d
//打印回应的头信息 Ol>q(-ea
public void logResponseHead(HttpURLConnection con) PFJ$Ia|
{ axnlI*!
for(int i=1;;i++) aJ+V]WmA
{ pp@ Owpb
String header=con.getHeaderFieldKey(i); V'i-pn2gyu
if(header!=null) '#+&?6p
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0vv~G\yM
Utility.log(header+" : "+con.getHeaderField(header)); }p~2lOI
else oPKLr31zt
break; p3M!H2W
} j9+4},>>CU
} WQ9e~D"
fQfn7FaW_\
(.4lsKN<
public void splitterStop() Tvx1+0Z%z
{ wo@ T@Ve~
bStop = true; OD8 fn
} aFTWzz
QF>T)1&J[7
&*v\t\]
} &en. m>9,
O&l4/RtQ\)
TDH^x1P
/* ~7 i{~<?
**FileAccess.java JIySe:p3
*//文件访问(定位，写) ^ }7O|Y7
package NetFox; E#J})cPzw
import java.io.*; f!'i5I]
UY(T>4H+h
]}v]j`9m%
public class FileAccessI implements Serializable{ b}K,wAx
pl]|yIZ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hP"2X"kz&
RandomAccessFile oSavedFile; {:1j>4m2
long nPos; BP3Ha8/X
1wR[nBg*|
dbby.%
public FileAccessI() throws IOException QHNyH
{ ~[%CUc"
this("",0); )]P(!hW.
} ,31 ? Aa
h1_Z&VJ
}-oba_
public FileAccessI(String sName,long nPos) throws IOException \|,| )
{ yx]9rD1cz
oSavedFile = new RandomAccessFile(sName,"rw"); P{o)Ir8Tt
this.nPos = nPos; ^QS`H@+Z
oSavedFile.seek(nPos); (Q8!5s
} G8av5zR
2{=]Pf
]E/0iM5
public synchronized int write(byte[] b,int nStart,int nLen) 1iF=~@Nz_
{ Pe_O(
int n = -1; ,jY:@<n
try{ yT7$6x
oSavedFile.write(b,nStart,nLen); 'I$FOH
n = nLen; N68mvBe
} ng%[yY
catch(IOException e) p>tkRA?lk
{ A*OqUq/H`;
e.printStackTrace (); .iy4 (P4
} ^+>*Y=fl
cB uuq
@ VWED
return n; w ,j*I7V
} NxHUOPAJc
X)3(.L
JWb +
} aC,adNub
p":u]Xgb
;E.]:Ia~
/* "6jt$-?
**SiteInfoBean.java QY;(Ny/(y
*/ !UoA6C:
package NetFox; nm5DNpHk
;I4vPh5Q
e8vy29\S
public class SiteInfoBean { KuP#i]Na
?06gu1z/
5Y *4a%"
private String sSiteURL; //Site's URL [^"*I.Z_
private String sFilePath; //Saved File's Path WGv47i
private String sFileName; //Saved File's Name ,j_js8r
private int nSplitter; //Count of Splited Downloading File T~E;@weR
z x-[@G
j}uL
public SiteInfoBean() >?@5>wF
{//nSplitter的缺省值为5 NW[K/`-CTH
//default value of nSplitter is 5 0"R>:f}
this("","","",5); DsMo_m/"1
} JR]2Ray
aF 2vgE\
/WnCAdDgZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F*KQhH7Gf
{ FSMM
sSiteURL= sURL; Ph=NH8
sFilePath = sPath; l2LQV]l
sFileName = sName; :Qge1/
this.nSplitter = nSpiltter; FOG{dio
x$d[Ovw-
h?xgOb!4
} p7|I>8ur.
d'';0[W)
X~r9yl>
public String getSSiteURL() LACrg
{ o ]*yI[\
return sSiteURL; x {NBhq(4
} D)PX|xrn
E*YmHJ:k
B=cA$620
public void setSSiteURL(String value) Ic0Sb7c
{ /GgID!8
sSiteURL = value; D)-LZbPa
} Jt[ug26
|?88EG@05
4;YP\{u
public String getSFilePath() QGpj$ _b
{ N?qETp-:
return sFilePath; _x.2&S89
} *HD(\;i-$
M`&t=0D
ZN}`A7
public void setSFilePath(String value) l!,tssQ
{ +v B}E
sFilePath = value; 2'fd4rE5
} O!"K'Bm
:tZsSK
d#T5=5#
public String getSFileName() J,W$\V]p
{ $+WXM$N
return sFileName; ^&<M""Z
} s&E,$|80
}uIQ@f`
?2"g*Bak
public void setSFileName(String value) jemb/:E
{ 5ngs1ZF@
sFileName = value; .eN"s'
} #mU\8M,
b:S$oE
9?\cm}^?
public int getNSplitter() hrKeOwKHU
{ 8]#FvgX
return nSplitter; ('7?"npd
} )x!q;^Js9A
+<\LY(o
8[@,i|kgg0
public void setNSplitter(int nCount) +'m9b7+v
{ zLl-{Kk
nSplitter = nCount; ->I.D?p
} FsqH:I4O
} 5X^\AW
X4o#kW
NV./p`k
/* (A?>U_@
**Utility.java YW7w>}aW
*/ %f;v$rsZ
package NetFox; HB )+.e
"[ S[vkI
x;W!sO@$
public class Utility { qXtC7uNj$
cpk\;1&t
=Z.0-C>W
public Utility() ?eTZ>o.p/
{ 7Q!ksp
[7><^?t V
diXWm-ZKL
} #f(a,,Uu'
"7sv@I_j
//线程睡眠 (7X
public static void sleep(int nSecond) QI[WXxp
{ uT]$R
try{ c%5P|R~g]p
Thread.sleep(nSecond); yM 7{v$X0
} J0Yb_(w
catch(Exception e) rTR$\ [C
{ \Hb!<mrp
e.printStackTrace (); ;I5P<7VW
} -+){;,
} {EZR}N
+\+j/sa
//日志 NzZ(Nz5
public static void log(String sMsg) p{oz}}
{ pq0Z<b;2
System.err.println(sMsg); $x}R2
} { 5r]G
/'8%=$2Kw
/[ m7~B]QE
public static void log(int sMsg) qD%88c)g
{ n_{&dVE
System.err.println(sMsg); J-+mdA
} Dh^l:q+c
} 7y^)n<'co
npeL1zO-$
O$z"`'&j#
/* d%}?%VH
**TestMethod.java $/^Y(0
*/ 3q4VH q
package NetFox; 48,*sTRq
[DpOI
G9xl-ag+z
public class TestMethod { iAe"oXK|
#TUm&2 +V
@|\;#$?XW3
public TestMethod() O4`.ohAZ
{ ///xx/weblogic60b2_win.exe Zs^zD;zU
try{ Q=!QCDO(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); tV4yBe<``
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dZ"}wKbO
SiteFileFetch fileFetch = new SiteFileFetch(bean); H.?`90IQ
fileFetch.start(); 4r;le5@
} hcU^!mp
catch(Exception e){e.printStackTrace ();} CXn?~m&K
EE09 Er%\
X,@nD@
} @j\;9>I/
;|T|*0vY[
Z^]Oic/0Oa
public static void main(String[] args) bh" Caz.(t
{ zk }SEt-
new TestMethod(); \>su97
} ,ng/T**@G
} PUea`rE?R
点击下载更多相关资料