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)); ZS@R?
} I;9DG8C&v*
for(int i=0;i<nEndPos.length-1;i++) JD AX^]
{ `_"?$ v2F
nEndPos = nStartPos[i+1]; C\|HN=2eh
} 2d<`dQY{l3
nEndPos[nEndPos.length-1] = nFileLength; Xob(4
} . ywVGBvJ
} 1KJ[&jS ]
G {a;s-OA3
5RYrAzQo
//启动子线程 1-R4A7+3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Bma.Uln
for(int i=0;i<nStartPos.length;i++) qSaCl6[Do
{ E.^u:0:P
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k\ZU%"^J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), pvRa
nStartPos,nEndPos,i); s&DAO r!i
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dQ#oY|a
fileSplitterFetch.start(); H{_6e6`e.
} lg 1r]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u:,B&}j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :%U lNk
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w2K>k/v{-
nEndPos = " + nFileLength); 6*I=% H|
// fileSplitterFetch[nPos.length-1].start(); t3!~=U
~$7YEs)
59?$9}ob
//等待子线程结束 HLh]*tQG
//int count = 0; lvUWs
//是否结束while循环 4hn'b[
boolean breakWhile = false; RVpo,;:
a!PN`N28
} OkK@8?0O
while(!bStop) )1O|+m k
{ 8{Vt8>4
write_nPos(); 9v7}[`^
Utility.sleep(500); =CaSd|
breakWhile = true; B;Co`o2
7}tXF
/8P7L'Rb
for(int i=0;i<nStartPos.length;i++) msw=x0{n5
{ X"T)X#:)
if(!fileSplitterFetch.bDownOver) @j%7tfW
{ +.X3&|@k
breakWhile = false; |Lc.XxBkc
break; F_V/&OV
} }w)wW1&
} 6O'Y@9#
if(breakWhile) h6D1uM"o
break; *C^TCyBK;
<h`}I3Ao
=z}M(<G
//count++; T`Xz*\}Zb
//if(count>4) >~T2MlRux
// siteStop(); [kI[qByf
} ,4(m.P10
WX$AOnEv
:/;;|lGw
System.err.println("文件下载结束！"); MhN8'y(
} )U{IQE;T#
catch(Exception e){e.printStackTrace ();} \Zn~y--Z
} Ystd[
`V?NS,@$
")W5`9
//获得文件长度 y"ms;w'z
public long getFileSize() Oq95zo
{ r<"k /
int nFileLength = -1; pAcu{5#7
try{ $u,`bX
URL url = new URL(siteInfoBean.getSSiteURL()); *,wW-8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UR[UZ4G
httpConnection.setRequestProperty("User-Agent","NetFox"); =AeOkie
No]#RvEd3
oCB#i~|>a
int responseCode=httpConnection.getResponseCode(); w5a;ts_x
if(responseCode>=400) u"kB`||(
{ s18A
processErrorCode(responseCode); Ia>~ph#]{`
return -2; //-2 represent access is error [Y6ZcO/-i
} gy/bA
IZZ $p{
,*;g+[Bhpl
String sHeader; ~&+8m=
4TaHS!9
A)nE+ec1
for(int i=1;;i++) {CGk9g"`
{ ymA8`k5>@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `(@{t:L
//Utility.log(in.readLine()); w#;y
sHeader=httpConnection.getHeaderFieldKey(i); SdJkno
if(sHeader!=null) z-`4DlJUS
{ 8|rlP
if(sHeader.equals("Content-Length")) 7*47mJyc
{ }kk[lvhJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Kuh)3/7
break; p[D,.0SuC
} l/bZE.GJ
} aOW$H:b
else 5+*CBG}
break; 2Vg+Aly4D
} FX/f0C3CK
} #vT~D>zj
catch(IOException e){e.printStackTrace ();} g|)yM^Vqr6
catch(Exception e){e.printStackTrace ();} ?;p45y~n%
V"|j Dnn5
v$R7"
Utility.log(nFileLength); mB*;>
wmit>69S
m?`$NJST
return nFileLength; YHo*IX')C?
} =|q@Q`DB
C0'_bTfB
D;X/7 p|>
//保存下载信息（文件指针位置） \xOv9(
private void write_nPos() aX35^K /
{ Mog!pmc{
try{ ImI,q:[67
output = new DataOutputStream(new FileOutputStream(tmpFile)); i7xBi:Si
output.writeInt(nStartPos.length); Bet?]4\_
for(int i=0;i<nStartPos.length;i++) /U"3LX
{ 5f#]dgBe
// output.writeLong(nPos); DbK-3F_
output.writeLong(fileSplitterFetch.nStartPos); S{qsq\X
output.writeLong(fileSplitterFetch.nEndPos); r1|;V~a$~
} bcFZ~B
output.close(); s!/Q>A
} s C?-L
catch(IOException e){e.printStackTrace ();} \v([,tiW%
catch(Exception e){e.printStackTrace ();} /@K1"/fqH
} o,=dm@j
&y:SK)
6>/g`%`N
//读取保存的下载信息（文件指针位置） e}W|wJ):j@
private void read_nPos() ,+E"s3NW
{ Z~DR,:
try{ }&IOBYHVDo
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]llvG\
int nCount = input.readInt(); jftf]n&Z(q
nStartPos = new long[nCount]; u/X1v-2
nEndPos = new long[nCount]; 0I[3%Q{
for(int i=0;i<nStartPos.length;i++) .T^e8
{ T3^(I~03
nStartPos = input.readLong(); CYN|
nEndPos = input.readLong(); ~ ^)4*@i6
} l\~F0Z/O
input.close(); EB[B0e7}
} lag%}^
catch(IOException e){e.printStackTrace ();} ^es/xt
catch(Exception e){e.printStackTrace ();} TllIs&MCe
} VAZ6;3@cd
k>72W/L^
hdx"/.s
private void processErrorCode(int nErrorCode) kV+O|9
{ PkxhR;4
System.err.println("Error Code : " + nErrorCode); r WPoR/M
} 2<Q3-|/i
0]`%iG|
Y` tB5P
//停止文件下载 x8E!Ko](
public void siteStop() BFMINq>
{ _9b;8%?Yf
bStop = true; OqA#4h4^
for(int i=0;i<nStartPos.length;i++) OG}m+K&<
fileSplitterFetch.splitterStop(); p*"H&xA@
tD\%SiTg=b
%P-z3 0FHp
} |fg{Fpc
} uY Y{M`
//负责部分文件的抓取 Kv-4VWh
**FileSplitterFetch.java eh}{\P
*/ SpiI9)gp
package NetFox; 3+2cD
e2$k %c~
o-%DL*^5
import java.io.*; FTC,{$
import java.net.*; G,JNUok
x9VR>ux&
AF-uTf
public class FileSplitterFetch extends Thread { fs wQ*
w#\*{EN
![4<6/2gy
String sURL; //File URL ) v^;"q"
long nStartPos; //File Snippet Start Position 8.4+4Vxh
long nEndPos; //File Snippet End Position \*k}RKDwT
int nThreadID; //Thread's ID eNw9"X}g
boolean bDownOver = false; //Downing is over @XFy^?
boolean bStop = false; //Stop identical b6A]/290x
FileAccessI fileAccessI = null; //File Access interface *&lNzz5&
%vFoTu)2
.3yxg}E>{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kA%"-$3
{ CP!>V:w%9!
this.sURL = sURL; $d_%7xx
this.nStartPos = nStart; E8s&.:;+
this.nEndPos = nEnd; U<H< !NV
nThreadID = id; yCT:U&8%F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6`Af2Y_
} eW^_YG%(
4` zfrT^
O+Qt8,
public void run() *%wfR7G[B
{ j=~c( B
while(nStartPos < nEndPos && !bStop) l2LUcI$ x
{ aL%amL6CX
?A7_&=J%
dwAFJhgh
try{ KM;'MlO
URL url = new URL(sURL); P(#by{s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7Ta",S@m
httpConnection.setRequestProperty("User-Agent","NetFox"); 8rx"D`{|
String sProperty = "bytes="+nStartPos+"-"; 3>t^Xu~
httpConnection.setRequestProperty("RANGE",sProperty); ME%W,B.|"s
Utility.log(sProperty); ;.4A,7w#
(( D*kd"
o:irwfArv
InputStream input = httpConnection.getInputStream(); ,3tcti~sZ
//logResponseHead(httpConnection); A$]&j5nh|
V)8d1S
,Bg)p_B
byte[] b = new byte[1024]; qFD#D_O6
int nRead; r|>a;nY
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1^4z/<ZWm
{ ``p()^zT
nStartPos += fileAccessI.write(b,0,nRead); -$js5Gx1
//if(nThreadID == 1) 0+P<1ui
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >u:t2DxE
} %8a886;2
#}Qzu~
mOkf
Utility.log("Thread " + nThreadID + " is over!"); 6*n<emP
bDownOver = true; P:gN"f6
//nPos = fileAccessI.write (b,0,nRead); ;P#c!
} xbv
catch(Exception e){e.printStackTrace ();} l].Gz`L
} toCxY+"nbU
} sw'?&:<"Ow
0[qU k(=}[
udV.$N
//打印回应的头信息 "A6T'nOP
public void logResponseHead(HttpURLConnection con) ]_WB^
{ _z$lg]q
for(int i=1;;i++) cnR.J
{ B8'e,9
String header=con.getHeaderFieldKey(i); "5,tEP!
if(header!=null) ,c;u]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <[eE5X(
Utility.log(header+" : "+con.getHeaderField(header)); oS/cS)N20
else N=QeeAI}}m
break; l12_&o"C~
} y(!YN7_A
} P~5[.6gW
)Uv lEG']
!5;A.f
public void splitterStop() jeM/8~^4-
{ [8o!X)
bStop = true; t)*MLg<C
} R\B-cU[,
nf7l}^/UE
eXqS9`zKr
} JQhw>H9&
:q xd])-
Xo{|m[,
/* Gs% cod
**FileAccess.java q@}eYQ=P|e
*//文件访问(定位，写) >+ZG{'!j
package NetFox; JToc("V
import java.io.*; &GC`4!H
dvAvG.;U
AI|8E8h+D
public class FileAccessI implements Serializable{ o6PDCaT7
Tjfg[Z/x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LyRU2A
RandomAccessFile oSavedFile; $cxulcay=
long nPos; ecoi4f
i+2fWi6Z+
-xc*R%k
public FileAccessI() throws IOException sMq*X^z )?
{ ;!JI$_-\
this("",0); S-^RZ"
} Ez*9*]O*+
wIv_Z^%V
CO`%eL~
public FileAccessI(String sName,long nPos) throws IOException V?a+u7*U&
{ b0A*zQA_)
oSavedFile = new RandomAccessFile(sName,"rw"); UKBVCAK
this.nPos = nPos; }w0>mA0=H
oSavedFile.seek(nPos); xMAfa>]{n
} Iq@:n_~
_\9|acFT2O
q\P"AlpC!
public synchronized int write(byte[] b,int nStart,int nLen) LG0z|x(
{ /$ -^k[%
int n = -1; H WOl79-
try{ $\0%"S
oSavedFile.write(b,nStart,nLen); PfaBzi9?f
n = nLen; J;K-Pv+
} Fo=hL
catch(IOException e) "pDwN$c
{ FZW)C'j
e.printStackTrace (); FJ|6R(T_
} cK;,=\
pohA??t2:
SD"'
return n; 7>Af"1$g
} x*G-?Xza)
CLb~6LD
+izB(E8&{J
} x-Kq=LFy.
Rn(vG-xQ
*?zyF@K{%
/* 9aED6
**SiteInfoBean.java :|s!_G<
*/ G8w<^z>pTg
package NetFox; O>Vb7`z0<
U;Iqz1S
^^u{W|'CaH
public class SiteInfoBean { hPs7mnSW
eY)JuJ?
g:l5,j.K
private String sSiteURL; //Site's URL woctnT%"Q/
private String sFilePath; //Saved File's Path nN=o/zd
private String sFileName; //Saved File's Name K0|8h!WF+
private int nSplitter; //Count of Splited Downloading File Ue>;h9^
~nQv yM!$
t:DZow
public SiteInfoBean() +:hZ,G?>
{//nSplitter的缺省值为5 E4a`cGb
//default value of nSplitter is 5 3yWu-U \k
this("","","",5); As&=Pb9
} k3[%pS
+1Qa7\
5J d7<AO_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [jPUAr}
{ `D0>L'
sSiteURL= sURL; j-egsKR
sFilePath = sPath; wA+QUN3#n
sFileName = sName; 39xAh*}G]
this.nSplitter = nSpiltter; )ZU)$dJ>V
K3uNR w
#kO.'oIl
} z=}@aX[
BT|5"b}
I7b_dJD;*
public String getSSiteURL() 9] i$`y
{ K.y2 $b/
return sSiteURL; C+,JLK
} =J2\"6BnzA
T6gugDQ~.
}:5_vH0
public void setSSiteURL(String value) Pc+8CuN?
{ mVJW"*}8
sSiteURL = value; DAZzc :1Aj
} g_kR5Wxpt
%\5wHT+)
3#{{+5G
public String getSFilePath() 83 O+`f
{ gnW]5#c@
return sFilePath; c-|~ABtEpX
} 8VbHZ9Q
fOE8{O^W
X2X.&^
public void setSFilePath(String value) 5H (CP
{ zh5$$*\
sFilePath = value; J^}w,r*=
} o5!"dxR
K4]42#
Rgb1B3gu
public String getSFileName() {`2R<O
{ >EVlMt27'
return sFileName; H3$~S '
} (AHZmi V
(8M^|z}q
e,Ih7-=Er,
public void setSFileName(String value) + 9vd(c
{ c6IFt4)g
sFileName = value; h5+qP"n!?q
} K"p$ga{
>Oary
@x9DV{j)V
public int getNSplitter() >d.o1<
{ ``%uq)G=D
return nSplitter; W<J".2D
} aBo8?VV]8
]_cBd)3P}
YeN /J.R
public void setNSplitter(int nCount) Y)?dq(
{ "`b"PQ<x
nSplitter = nCount; n5nV461U
} @,Je*5$o"
} #41fRmzC
kOv2E]
[;bZQ6JR
/* TTg>g~t`
**Utility.java @]*b$6tt
*/ v&BKl
package NetFox; gv&%2e}_
nZ;h&N-_-
pEUbP,3M:
public class Utility { O]ZP- WG
'qGKS:8
czMu<@c [
public Utility() bFivHms
{ 8.Q;o+NU
NGl/F{<
TW2OT }
} MA\^<x_?L}
71AR)6<R
//线程睡眠 ;DMv?-H
public static void sleep(int nSecond) yN*HIN
{ }E=:k&IDPB
try{ D`nW9i7
Thread.sleep(nSecond); Yg 8AMi
} 2ckAJcpEb/
catch(Exception e) d/Q}I[J.u
{ kF:4[d
e.printStackTrace (); 19 h7 M
} A>;Q<8rh
} VE4Z;Dr"
,|gX?[o
//日志 K".\QF,:
public static void log(String sMsg) GF6c6TXF@
{ 2?3D` `
System.err.println(sMsg); ;^5d^-T
} .&:GOD
GA19=gow
bM]\mo>z<
public static void log(int sMsg) @(XX68
{ &Gp~)%
System.err.println(sMsg); x+j5vzhG)
} t`b>iX%(1t
} ->DfT*)
cY+vnQm
y %dUry%>
/* Fs^d-I
**TestMethod.java kV@*5yc?R
*/ cswX?MN
package NetFox; ?Ji.bnfK
I(6k.PQ
!FhK<#
public class TestMethod { Cm:&n|
lO482l_t
,vBi)H
public TestMethod() (2He]M\
{ ///xx/weblogic60b2_win.exe fH_G;#q
try{ xPa>-N=*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {^TVZdw
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Pb0+z=L
SiteFileFetch fileFetch = new SiteFileFetch(bean); *ey<R
fileFetch.start(); >n,RBl
} 5#~ARk*?a
catch(Exception e){e.printStackTrace ();} SB#YV
wAHW@q9CK
.r9-^01mG
} :tP:X+?O
%N\pfZ2\
,BM6s,\
public static void main(String[] args) 9*!C|gC9Ia
{ <v<TsEI
new TestMethod(); nQ\ +Za==
} q7}$F]UM"
} "hRw_<
点击下载更多相关资料