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)); vr5<LNCLQ
} (8+.#1!*
for(int i=0;i<nEndPos.length-1;i++) M nH4p
{ }|AUV
nEndPos = nStartPos[i+1]; %'k^aqFL
} oy#Qj3M8=
nEndPos[nEndPos.length-1] = nFileLength; wGLZzqgq
} PL%_V ?z
} nuhKM.a{
&kYg >X
#RZW)Br
//启动子线程 ),dXaP[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vYrqZie<
for(int i=0;i<nStartPos.length;i++) mqw&SxU9
{ h-Ffs
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VmV/~-<Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !W .ooy5(
nStartPos,nEndPos,i); m~#98ZJ^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h]vA%VuE'E
fileSplitterFetch.start(); T+N%KRl
} V 7%rKK
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 97'*Xq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V= !!;KR0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |u7vY/
nEndPos = " + nFileLength); `NyvJt^<
// fileSplitterFetch[nPos.length-1].start(); _z{:Q
+hV7o!WxC
56d,Sk)
//等待子线程结束 $>]7NTP
//int count = 0; bC)diC
//是否结束while循环 "*XR'9~7
boolean breakWhile = false; L%U-MOS=
qL UbRp
=<n+AqJ%
while(!bStop) *siS4RX2
{ |*i0h`a
write_nPos(); kImS'i{A
Utility.sleep(500); '-S^z"ZrI
breakWhile = true; u ;f~
Z&/bp1
SA)}---"
for(int i=0;i<nStartPos.length;i++) #3\F<AJ<VB
{ u])N^AY"sj
if(!fileSplitterFetch.bDownOver) 50uNgLs
{ /i"L@t)\t
breakWhile = false; YeptYW@xfw
break; _;L9&>!p6
} i|)<#Ywl
} 1^b-J0
if(breakWhile) _Cj u C`7
break; mp+ %@n.;
4}gqtw:
q.g<gu]
//count++; L6J=m#Ld
//if(count>4) s+h`,gg9
// siteStop(); BC9rsb
} <Gr{h>b
_U|s!60'
|Q?IV5%$
System.err.println("文件下载结束！"); w8%<O^wN,
} 1|q$Wn:*
catch(Exception e){e.printStackTrace ();} )$]_;JFr
} {: T'2+OH>
gH(,>}{^K
K8ecSs}}J
//获得文件长度 b'3w.%^
public long getFileSize() 'Oyz/P(p
{ /{."*jK
int nFileLength = -1; <A;R%\V
try{ w|OMT>.
URL url = new URL(siteInfoBean.getSSiteURL()); v\'Eo*4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Pp*|EW 1
httpConnection.setRequestProperty("User-Agent","NetFox"); WIa4!\Ky!
\|L ~#{a
Y?{L:4cRX
int responseCode=httpConnection.getResponseCode(); b$l@Z&[]
if(responseCode>=400) +DY%Y `0
{ %D)W~q-g
processErrorCode(responseCode); Ze~^+ EE
return -2; //-2 represent access is error Rjqeuyj:
} _%?}e|epy
'+hiCX-_
qfd/t<?|D
String sHeader; Cb%?s
oe=^CeW"
4. 7m*
for(int i=1;;i++) _{_ybXG|
{ 1(CpTaa
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WV]Si2pOZ
//Utility.log(in.readLine()); <7~HG(ks
sHeader=httpConnection.getHeaderFieldKey(i); U,_uy@fE=?
if(sHeader!=null) ps\A\aggML
{ _?x*F?5=
if(sHeader.equals("Content-Length")) b%IRIi&,
{ m-xSF]q=<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); PO%Z.ol9
break; LBh|4S$K
} rwWs\~.H
} :aS8%m
else F4xYfbwY"]
break; R^.E";/h
} w+)MrB-}
} lfba
catch(IOException e){e.printStackTrace ();} 6",S$3q
catch(Exception e){e.printStackTrace ();} s2FJ^4
z@R:~
8J-$+ ;
Utility.log(nFileLength); :G=N|3
0,a\vs%@X
b)"bX}
return nFileLength; t:B~P,r
} Rf||(KC<
7s+3^'
+&6R(7XC
//保存下载信息（文件指针位置） hsr,a{B%$
private void write_nPos() LmE%`qNg
{ 2Dgulx5kGZ
try{ ]:uJ&xUar
output = new DataOutputStream(new FileOutputStream(tmpFile)); `md)|PSU
output.writeInt(nStartPos.length); r-&Rjg
for(int i=0;i<nStartPos.length;i++) DgQw`D)+
{ H`odQkZ!
// output.writeLong(nPos); `CP#S7W^
output.writeLong(fileSplitterFetch.nStartPos); 9%55R >s$
output.writeLong(fileSplitterFetch.nEndPos); FR"yGx#$
} fs_6`Xt
output.close(); gVO<W.?
} 7D PKKvQ
catch(IOException e){e.printStackTrace ();} ,Dd )=
catch(Exception e){e.printStackTrace ();} 6c>cq\~E
} 96x$Xl;
| #Z+s-
sOQF_X(.x
//读取保存的下载信息（文件指针位置） r%QTUuRXC3
private void read_nPos() In<L?U?([D
{ sH(@X<{p
try{ `"`/_al^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xF![3~~3[
int nCount = input.readInt(); 7DQ{#Gf#G
nStartPos = new long[nCount]; Z.TYi~d/9D
nEndPos = new long[nCount]; pxy=edd
for(int i=0;i<nStartPos.length;i++) ' P5ttI#|
{ zg L0v5vk
nStartPos = input.readLong(); {=};<;_F
nEndPos = input.readLong(); Qk2^p^ T6
} +ExXhT
input.close(); N.R,[K
} ?"-%>y@w
catch(IOException e){e.printStackTrace ();} ElLDSo@WvR
catch(Exception e){e.printStackTrace ();} -]HPDN,OB
} *-0tj~)>
H <7r
ntK#7(U'
private void processErrorCode(int nErrorCode) 0wL-Ak#v
{ 6^_:N1@
System.err.println("Error Code : " + nErrorCode); T:k-`t0":N
} /<ODP6Yy;
GxjmHo
BSU%.tmI
//停止文件下载 2IDN?Mw
public void siteStop() 3<">1] /,
{ @)nxX))a
bStop = true; [HNWM/ff7+
for(int i=0;i<nStartPos.length;i++) \[u7y. b
fileSplitterFetch.splitterStop(); =M39I&N
l`"i'P
{6}H}_(]
} \o}m]v i
} A9qbE
//负责部分文件的抓取 5A^$!q P
**FileSplitterFetch.java 3jH-!M5
*/ )*6]m1
package NetFox; od\-o:bS
a;@G
7tbM~+<0
import java.io.*; "%^T~Z(_j
import java.net.*; jFAnhbbCE
W>[0u3
-36pkC 6 \
public class FileSplitterFetch extends Thread { L>:YGM"sL
(|Zah1k&]
}C6RgE.6<
String sURL; //File URL jNjm}8`t
long nStartPos; //File Snippet Start Position Yu1[`QbB
long nEndPos; //File Snippet End Position )P>-~G2P
int nThreadID; //Thread's ID BF >678h
boolean bDownOver = false; //Downing is over <WPLjgtn3
boolean bStop = false; //Stop identical ,dyCuH!B
FileAccessI fileAccessI = null; //File Access interface z _A]mJ
9:[L WT&
.r=F'i}-j*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `Ckx~'1M:
{ Cf&.hod
this.sURL = sURL; qpjG_G5/
this.nStartPos = nStart; Obj?,O
this.nEndPos = nEnd; AW[_k%
nThreadID = id; IhRWa|{I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2^3N[pM;
} hW~XE{<
o'#ow(X
<4{Jm8zJ
public void run() yAyq-G"sO
{ gjbSB6[
while(nStartPos < nEndPos && !bStop) Ad%3 fvn
{ V:Z}cfR.7
cUB+fH<B2
MjjN
try{ 3_5]0:?]-
URL url = new URL(sURL); 7~f"8\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y'{*B(
httpConnection.setRequestProperty("User-Agent","NetFox"); \7\7i-Vo
String sProperty = "bytes="+nStartPos+"-"; kuX{2h*`
httpConnection.setRequestProperty("RANGE",sProperty); 8gIf
Utility.log(sProperty); zyh #ygH
+xL*`fn
78u9> H
InputStream input = httpConnection.getInputStream(); :"im2J
//logResponseHead(httpConnection); tjId?}\
ORdS|y;:
t5M"M{V
byte[] b = new byte[1024]; @,\J\ rb
int nRead; OZSM2~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _G62E$=
{ v9_7OMl/x
nStartPos += fileAccessI.write(b,0,nRead); *mVQN1
//if(nThreadID == 1) 7A=*3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jl)7Jd
} pRez${f.(s
C{<dzooz
ey/=\@[p
Utility.log("Thread " + nThreadID + " is over!"); Z!81\5
bDownOver = true; ~!iZn
//nPos = fileAccessI.write (b,0,nRead); 3!*qB-d
} )?$zY5
catch(Exception e){e.printStackTrace ();} 7.W$6U5
} YLU.]UC
} "?n;dXYSi
tmgZNg
.[Nr2w:>
//打印回应的头信息 VLP'3 qX
public void logResponseHead(HttpURLConnection con) hf1h*x^J
{ N2Qb+
for(int i=1;;i++) x1'4njTV$
{ K2@],E?e%|
String header=con.getHeaderFieldKey(i); a)qlrtCl
if(header!=null) k )=Gyv<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zPyN2|iFah
Utility.log(header+" : "+con.getHeaderField(header)); $a.,;:
else <KEVA?0>
break; MD+e!A#o
} )TtYm3,
} G]k+0&X
c*DBa]u2
#J`MR05
public void splitterStop() k8S`44vj
{ XbYST%|.
bStop = true; |Ca %dg9$@
} +]$c+!khj
W6!o=()
pzFM#
} 557%^)v
;4Wz0suf
uMb[0-5
/* 4sM9~zC5
**FileAccess.java m;oCi}fL
*//文件访问(定位，写) I2^@>/p8\(
package NetFox; m_C#fR /I
import java.io.*; D^<5gRK?
B{2WvPX~q
1`F25DhhY
public class FileAccessI implements Serializable{ X 3(CY`HH[
n^2'O:Vs
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v&3 Oc
RandomAccessFile oSavedFile; [+(fN
long nPos; w@i;<LY.
wfq}NK;
P,*yuF|bk
public FileAccessI() throws IOException 30<3DA_P
{ z *~rd2
this("",0); 5{\;7(
} `^'0__<M
aBT8mK -.
P:k!dRb9{
public FileAccessI(String sName,long nPos) throws IOException TFYp=xK(
{ VX,@Gp_'m
oSavedFile = new RandomAccessFile(sName,"rw"); a'|/=$
this.nPos = nPos; ~ea&1+Z[3
oSavedFile.seek(nPos); evro]&N{
} ZeE(gtM
!I+F8p
v])R6-T-
public synchronized int write(byte[] b,int nStart,int nLen) sHm:G_
{ |l673FcJ
int n = -1; )Kg_E6
try{ }cd-BW
oSavedFile.write(b,nStart,nLen); r`A|2(h5B
n = nLen; tr$d?
} n{E9p3i
catch(IOException e) aB)G!Rm&
{ sV-UY!
e.printStackTrace (); XBN,{
} dEK bB
G4QsR7
#bCzWg
return n; u=&$Z
} VNHt ]Ewj
*#c^.4$'
Qo])A6$IU
} g#r,u5<*?
eGi|S'L'
jGFDj"Y
/* ;-d2~1$
**SiteInfoBean.java ydf;g5OZ
*/ !Tu4V\^~A
package NetFox; ^/"2s}+
*@[N~:z/
e<-^
public class SiteInfoBean { w_9[y
c2Up<#t
"Tc[1{eI
private String sSiteURL; //Site's URL &d i=alvv1
private String sFilePath; //Saved File's Path `!7QegJa"
private String sFileName; //Saved File's Name ^|lG9z%Foy
private int nSplitter; //Count of Splited Downloading File MB3 N3,yL
a 8.Xy])!
:B1a2Y^"
public SiteInfoBean() Vho^a:Z9}W
{//nSplitter的缺省值为5 &1M#;rE;D#
//default value of nSplitter is 5 Jec<1|
this("","","",5); T8\%+3e.
} p5 )+R/
)ioIn`g^-
fhbILg
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;ksxz
{ (5&l<u"K~
sSiteURL= sURL; &E$:^a4d
sFilePath = sPath; p^i]{"sjbU
sFileName = sName; *kKdL
this.nSplitter = nSpiltter; jWJ/gv~ $
u,),kj<
e3x;(@j
} 73tWeZ8rvx
NK|m7(
*tL1t\jY
public String getSSiteURL() +<W8kb
{ ]_&pIBp
return sSiteURL; tqT-9sEXX.
} bZi;jl
`)_11ywZ
iYl$25k/1
public void setSSiteURL(String value) @d_;p<\l
{ V9<CeTl'
sSiteURL = value; (]*!`(_b
} 2Wq/_:
u}BN)%`B
hP26Bb1
public String getSFilePath() atWB*kqI
{ 6Rc%P)6
return sFilePath; S[L2vM)
} 7T@"2WYat
3:G94cp5
kU$M 8J.
public void setSFilePath(String value) j aq/]I7
{ ljRR{HOl
sFilePath = value; qr[+^*Ha
} DU.[Sp
R22P ol
+Y|HO[
public String getSFileName() *r]Mn~3
{ Ax"I$6n>
return sFileName; h2#S ?
} W(&9S[2
rkC6-9V
P g1EE"N@
public void setSFileName(String value) 1[r;
{ \J?5Kl[*c
sFileName = value; {uuvgFC
} I6,sN9` K
6mbHfL>cO
d( +E0
public int getNSplitter() XG_Iq ,
{ UONW3}-
return nSplitter; 7]6HXR@
} A1nEp0%Y
M/^kita
2gbMUdpp
public void setNSplitter(int nCount) ~TEKxgU
{ g&6O*vx
nSplitter = nCount; 4Iou| H
} "JCvsCe
} Al(u|LbQ
:i_kA'dl&
/o=,\kM
/* p$A`qx<M_
**Utility.java 95CCje{o_
*/ smt6).o
package NetFox; jboQ)NxT!,
M=aWL!nJ
>J[Wd<~t
public class Utility { B[rxV
(" +/ :
C6`<SW
public Utility() $k&}{c8P
{ l TJqWSV=f
%<Q?|}
Bz#K_S
} 63?fn~0\
MJ:>ZRXCE
//线程睡眠 :,^pLAt
public static void sleep(int nSecond) q$=EUB"C
{ >@o}l:*
try{ (W l5F
Thread.sleep(nSecond); 32*FISH^
} 'ehJr/0&g
catch(Exception e) ,3{z_Rax-
{ n/3gx4.g
e.printStackTrace (); t"@:a Y"
} #j{!&4M
} @BZ6{@*
"wPFQXU
//日志 "jUr[X2J
public static void log(String sMsg) K$..#]\TM
{ =Xc[EUi<;g
System.err.println(sMsg); g(0 |p6R
} =*YK6
_ .%\czO
YJ`[$0mam
public static void log(int sMsg) r4~Bn7j2
{ icf[.
System.err.println(sMsg); Pe !eID8
} i7[CqObzc
} Q\~4J1
[k9aY$baT^
$z+iB;x
/* [z:bnS~yiD
**TestMethod.java $3!j1
*/ k]Y#-Q1p~
package NetFox; `1NxS35u
:I5]|pt
OT9\K_
public class TestMethod { {q1&4U~'>O
S4]xxc
nr>g0_%m
public TestMethod() ]8q5k5~
{ ///xx/weblogic60b2_win.exe q)ygSOtj
try{ )-9G*3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0O>8DX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nzTzc5 w
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9_rNJLj8y
fileFetch.start(); pQxaT$
} .6[xX?i^T
catch(Exception e){e.printStackTrace ();} =>hq0F4[;
WG;1[o&
?'K}bmdt}.
} 8Us5Oi
k})Ag7c
9BGPq)#
public static void main(String[] args) Jr18faEZw
{ .e2u)YqA
new TestMethod(); ?rQMOJR
} 82*nC!P3E
} rZSD)I
点击下载更多相关资料