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)); 0;:.B j
} Wr3mQU
for(int i=0;i<nEndPos.length-1;i++) [I$BmGQ
{ \e'R@
nEndPos = nStartPos[i+1]; <p\6AnkMr
} YJ;j x0
nEndPos[nEndPos.length-1] = nFileLength; |*'cF-lp6v
} MF'$~gxo
} G1"zElug
0DmMG
(h5'9r
//启动子线程 Ar:*oiU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !2'jrJGc
for(int i=0;i<nStartPos.length;i++) -sjd&)~S[
{ ( |PAx(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \CXQo4P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :I:!BXQT$
nStartPos,nEndPos,i); 4x;/HEb7?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?kZTI (
fileSplitterFetch.start(); {FIXc^m'
} %QKRFPYhS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2cqI[t@0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x7<\]94
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =}v}my3y"
nEndPos = " + nFileLength); j|/]#@Yr
// fileSplitterFetch[nPos.length-1].start(); Okm{Xx
C_n9T{k
ni6{pK4Wqm
//等待子线程结束 zSSB>D
//int count = 0; @*Wh
//是否结束while循环 .Y3pS/VI
boolean breakWhile = false; z(fAnn T?
+S R+x/?z
z[cyA.
while(!bStop) f~dd3m('
{ ld^=#]g
write_nPos(); \z$p%4`E@
Utility.sleep(500); &Ibu>di4[
breakWhile = true; Ka6,<C o
|d*&y#kV
hlJq-*6'
for(int i=0;i<nStartPos.length;i++) rfgI$eu
{ S6+y?,^
if(!fileSplitterFetch.bDownOver) Wo7F
{ >OG:vw)E
breakWhile = false; phn9:{TI
break; nD)K}4
} P4F3Dc
} {iv<w8CU)
if(breakWhile) l411a9o
break; O=$~O\}b
9$Xu,y
2Ri{bWi
//count++; P#_sg0oJF
//if(count>4) 9(5OeH6o?
// siteStop(); GHsilba
} qnoNT%xazo
s_> f5/i2
CMCO}#
System.err.println("文件下载结束！"); |R56ho5C
} r4QxoaM
catch(Exception e){e.printStackTrace ();} 3q'&j,,^
} rc/nFl6#
8:#rA*Y
Ci<ATho
//获得文件长度 }yJ$SR]t
public long getFileSize() e89Xb;;w
{ ]]&M@FM2z
int nFileLength = -1; u6_@.a}
try{ ~-dV^SO
URL url = new URL(siteInfoBean.getSSiteURL()); &3$z4df
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *=wYuJ#
httpConnection.setRequestProperty("User-Agent","NetFox"); }t;(VynV)
V0%V5>
wAz&"rS
int responseCode=httpConnection.getResponseCode(); qR8u$2}NY
if(responseCode>=400) L}FOjrN
{ HS.^y x
processErrorCode(responseCode); >TP7 }u|
return -2; //-2 represent access is error CXO2N1~(J
} S=nP[s
`"@g8PWe
}Y*VAnY6;
String sHeader; '/$d0`3B>
,N e;kI
OI?K/rn
for(int i=1;;i++) ph_4q@
{ PIWux{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); IR-dU<<9O
//Utility.log(in.readLine()); svuq gSn
sHeader=httpConnection.getHeaderFieldKey(i); w1Ec_y{
if(sHeader!=null) >^Yq|~[
{ DF g,Xa#
if(sHeader.equals("Content-Length")) h^*4}GU
{ /MF!GM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hTM[8 ~<^
break; ~O]]N;>72"
} V~hlq$jn<Y
} PZm:T+5H
else PNA\ TXT
break; Y)$ ;Ax-D
} T`9u!#mT=
} VL/|tL>E^
catch(IOException e){e.printStackTrace ();} mCWhUBghR
catch(Exception e){e.printStackTrace ();} BA:yQ
2PeR
E^rbcGJ
Utility.log(nFileLength); \/SQ,*O
H{AMZyV0/d
PI~1GyJr@;
return nFileLength; [b/k3&O'
} k $fGom
?0 m\(#
vNeCpf
//保存下载信息（文件指针位置） .!6>oL/iF
private void write_nPos() tU^kQR!
{ \y88d4zX
try{ a3VM'
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8NU`^L:1
output.writeInt(nStartPos.length); *5wu
for(int i=0;i<nStartPos.length;i++) uu/+.9
{ d @*GUmJ
// output.writeLong(nPos); [F*4EGB
output.writeLong(fileSplitterFetch.nStartPos); [ G e=kFB
output.writeLong(fileSplitterFetch.nEndPos); -PnyZ2'Z
} Wfz\`y
output.close(); gxT4PQDy
} s%!`kWVJ.
catch(IOException e){e.printStackTrace ();} /%I7Vc
catch(Exception e){e.printStackTrace ();} N~?{UOZd
} LFZiPu
GCttXAto
=L5GhA~
//读取保存的下载信息（文件指针位置） `g_"GE
private void read_nPos() p)=~% 7DV
{ YqV8D&I
try{ 4:sjH.u<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HeK h>
int nCount = input.readInt(); 6SC,;p=
nStartPos = new long[nCount]; ZZj~GQL(S
nEndPos = new long[nCount]; a2f^x@0k
for(int i=0;i<nStartPos.length;i++) Y9=(zOqv
{ 6MG9a>=
nStartPos = input.readLong(); {0@&OO:w
nEndPos = input.readLong(); +@Ad1fJi
} Pa^A$fy\
input.close(); |w*R8ro_
} H Y ynMP
catch(IOException e){e.printStackTrace ();} g'l?~s`SB
catch(Exception e){e.printStackTrace ();} DS2)@
} 7P B)'Wl"6
3s:%2%jVK
+'G0{;b
private void processErrorCode(int nErrorCode) H3H_u4_?SE
{ x-'~Bu
System.err.println("Error Code : " + nErrorCode); XG@`ZJhU6
} J@L9p46,
Dl&GJ`&:p
<X_!x_x
//停止文件下载 !~ZP{IXyo
public void siteStop() <N(oDaU
{ axk"^gps
bStop = true; s 1ge0~p3
for(int i=0;i<nStartPos.length;i++) aP&D9%5
fileSplitterFetch.splitterStop(); }6-ZE9H-v
ow/57P
XYH|;P6K
} hAqg Iu*
} >|o_wO
//负责部分文件的抓取 phYDs9-K
**FileSplitterFetch.java /U$8TT8+-
*/ 45@]:2j
package NetFox; 5y} v{Ijt
!$g+F(:(c
0fs$#j
import java.io.*; >qo~d?+
import java.net.*; =pIy
hKlZi!4J
` r']^ ,
public class FileSplitterFetch extends Thread { Ao7`G':
aVe/ gE
b}G24{
String sURL; //File URL 3I|3wQ&#(
long nStartPos; //File Snippet Start Position }sxn72,
long nEndPos; //File Snippet End Position {C^@Q"I
int nThreadID; //Thread's ID FZH\Q~IUV
boolean bDownOver = false; //Downing is over Bd3~EbFL
boolean bStop = false; //Stop identical xAwf49N~
FileAccessI fileAccessI = null; //File Access interface [`Cq\mI-W
up%Z$"Y
eV6o3u:9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Hwm?#6\5
{ jko"MfJ
this.sURL = sURL; 2uk x (Z
this.nStartPos = nStart; 7@PIM5h
this.nEndPos = nEnd; [<wbbvXR
nThreadID = id; RiO="tX'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gcJF`H/iNK
} -@IL"U6
\Xt)E[
Ze!92g
public void run() Iia.k'N
{ `!G7k
while(nStartPos < nEndPos && !bStop) ^ie^VY($
{ A%vsno!
cgj.e
On1v<SD$[
try{ #vf_D?^
URL url = new URL(sURL); l#@&~f[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z}.D" P+
httpConnection.setRequestProperty("User-Agent","NetFox"); cX At:m
String sProperty = "bytes="+nStartPos+"-"; *C,N'M<u
httpConnection.setRequestProperty("RANGE",sProperty); /.=r>a}l
Utility.log(sProperty); yu ,h\
&!y]:CC{
mEQ!-p
InputStream input = httpConnection.getInputStream(); {$^SP7qV#>
//logResponseHead(httpConnection); !Zbesp KZ
-)<mS
2 Y|D'^
byte[] b = new byte[1024]; ., :uZyG
int nRead; _1jw=5^P\i
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cCxi{a1uo
{ >]}yXg=QK+
nStartPos += fileAccessI.write(b,0,nRead); +#]|)VZ
//if(nThreadID == 1) "]t>ZT:OJ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IX?ZbtdX$`
} }`9`JmNM
C$#W{2x%6
16@);Ot
Utility.log("Thread " + nThreadID + " is over!"); w}M3x^9@
bDownOver = true; ^C9x.4I$)
//nPos = fileAccessI.write (b,0,nRead); G5{Ot>;*%
} oA~4p(
catch(Exception e){e.printStackTrace ();} `W[+%b
} P 4;{jG
} &.*uc|{
B50 [O!
(BERY
//打印回应的头信息 k_3j '
public void logResponseHead(HttpURLConnection con) qa}>i&uO
{ 74zSP/G'
for(int i=1;;i++) ;o$;Z4:.D
{ MB*u-N0v
String header=con.getHeaderFieldKey(i); 4&N$:j<
if(header!=null) 6~Wu`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); viuiqs5[Bi
Utility.log(header+" : "+con.getHeaderField(header)); Yjup
else JfTfAq]
break; FD6v/Y
} q{X T
} n9fk,3
"g `nsk
(G8
public void splitterStop() _=6OP8
{ 3C"_$?y"
bStop = true; vF>gU_gz.
} Yg6I&#f7&
+p?hGoF=
'XTs -=
} h#{T}[
93I'cWN
55hyV{L%
/* GOW"o"S
**FileAccess.java p`GWhI?
*//文件访问(定位，写) ek[kq[U9
package NetFox; Igjr~@#
import java.io.*; Ky&KF0
uu>lDvR*
] C,1%(
public class FileAccessI implements Serializable{ 6wpU6NU
b}%g}L D
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0 [i+
RandomAccessFile oSavedFile; 5T/J%
long nPos; y[:q"BB3
ny`(f,)u*
&r:m&?!|VQ
public FileAccessI() throws IOException /p$=Cg[K
{ l<2oklo5
this("",0); pb$fb
} $WNG07]tU
m;h<"]<
6{7 3p@
public FileAccessI(String sName,long nPos) throws IOException ycjJbL(.
{ B+Q+0tw*i
oSavedFile = new RandomAccessFile(sName,"rw"); =xBT>h;
this.nPos = nPos; !~d'{sy6
oSavedFile.seek(nPos); Yzd2G,kZ=
} OMd# ^z
=yh3Nd:u
( 2zeG`
public synchronized int write(byte[] b,int nStart,int nLen) &A"e,h(^
{ p1 4d,}4W
int n = -1; b8HE."*t
try{ U"B.:C2
oSavedFile.write(b,nStart,nLen); t{=i=K3
n = nLen; M@~o6^
} 7O461$4v
catch(IOException e) =z-5
{ 0dh#/
e.printStackTrace (); A|C_np^z2
} M*H< n*
E&9!1!B
leIy|K>\m
return n; 1uC;$Aj6:
} ^5>du~d
"<*nZ~nE)
8;8YA1@w
} {,F/KL^u
gr\@sx?b
<p)Z/
/* lO_c/o$
**SiteInfoBean.java :Q=z=`*2w
*/ UnjNR[=
package NetFox; 6s5b$x
,$BgR2^
;24'f-Eri
public class SiteInfoBean { -s89)lUkS
j Ii[
vu ?3$
private String sSiteURL; //Site's URL U,38qKE
private String sFilePath; //Saved File's Path a6qwL4
private String sFileName; //Saved File's Name \2Xx%SX
private int nSplitter; //Count of Splited Downloading File vQy$[D*
08O7F
3/l\ <{
public SiteInfoBean() u6p5:oJj,
{//nSplitter的缺省值为5 ,,}sK
//default value of nSplitter is 5 ~BtKd*~*
this("","","",5); s~)L_ p
} f^u^-l
J& )#G@fRX
iz$FcA]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) n_u`B|^Pj
{ ]xI?,('_m
sSiteURL= sURL; PC[cHgSYU
sFilePath = sPath; gjQ=8&i
sFileName = sName; vi<X3G6Xh
this.nSplitter = nSpiltter; Fj,(_^
/_HwifRQ
d>;2,srUf
} o|+E+l9\
}R`Irxv4
=Iy/cHK
public String getSSiteURL() Dw*Arc+3V
{ -}<d(c
return sSiteURL; :;q>31:h
} &q"'_4
R|$[U
xHm/^C&px
public void setSSiteURL(String value) 0FTRm2(
{ (GnVwJ<v9V
sSiteURL = value; [\88@B=jXP
} Et)920
_ r~+p
'HJ/2-=
public String getSFilePath() T^N L:78
{ t18UDR{
return sFilePath; v&e-`.xR
} 6#fOCr;f7
T7^ulG1'
YN4"O>
public void setSFilePath(String value) \m%J`{Mt
{ g%X&f_@
sFilePath = value; O1|B3M[P
} G&.d)NfE
jT{f<P0
.|U4N/XN%q
public String getSFileName() L>0!B8X2
{ kpl~/i`4
return sFileName; Y:rJK|m
} NoJUx['6
I Jqv w
6aRGG+H
public void setSFileName(String value) P$6W`^DZ
{ 2rF?Q?$,B
sFileName = value; B'<!k7Ewy
} \y[Bu^tk
~."!l'a
lfXH7jL2~
public int getNSplitter() yLjV[qP
{ +g)_4fV0|
return nSplitter; AS`2=w
} lt{lHat1
kV_#9z7%
Ft)t`E'%j
public void setNSplitter(int nCount) qo)Q}0
{ S^|$23}
nSplitter = nCount; ,Y$F7&
} } /[_
} z~BD(FDI
k& WS$R?u
]cn/(U`
/* Fq vQk
**Utility.java t8t}7XD
*/ R:]/{b4Uq
package NetFox; gW'P`Oxw
uE"5cq'B/
dFdlB`L
public class Utility { $*YC7f
u)tHOV>&
8mk}nex
public Utility() T"n>h
{ TNyK@~#m
oG+K '(BB
AGl|>f)
} zhuyePn
i/5y^
//线程睡眠 g@<sU0B
public static void sleep(int nSecond) wEBtre7
{ zt-'SY
try{ 9 %D$T'K
Thread.sleep(nSecond); c9\B[@-q
} os}b?I*K
catch(Exception e) yT[Lzv#
{ J"/JRn
e.printStackTrace (); \_lG#p|
} |P^]@om
} BjH~Ml2
,DexJ1
//日志 M4zX*&w.T
public static void log(String sMsg) "L9C
{ NE$VeW+@
System.err.println(sMsg); '9IP;
} zY]Bu-S3
n^* >a
@*CAn(@#N
public static void log(int sMsg) ;[;)P tFz\
{ LN@lrC7X
System.err.println(sMsg); %T`4!:vy
} q:TZ=bs^
} fn1 ?Qp|
H;b8I
cYZwWMzp
/* wrz+2EP`
**TestMethod.java \Ku9"x
*/ 'dmp4VT3
package NetFox; "}S9`-Wd|
[54@irH
IW5*9)N?
public class TestMethod { [>b '}4
2q`)GCES~
+CsI,Uf4*
public TestMethod() >v^2^$^u
{ ///xx/weblogic60b2_win.exe Am>_4
try{ s$f+/Hs
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >E//pr)_Km
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zkjPLeX
SiteFileFetch fileFetch = new SiteFileFetch(bean); hknwis%y
fileFetch.start(); fl} rz
} E9yFREvQc
catch(Exception e){e.printStackTrace ();} 6'RZ
Z-N-9E
$w|o@ Ml)
} :SpG&\+
Y&?|k'7
UI|v/(_^F
public static void main(String[] args) 03X<x|
{ DZHrR:q?e
new TestMethod(); t` }20=I+
} 9F2w.(m
} c*y$bf<
点击下载更多相关资料