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)); }Z`@Z'
} 4;w#mzd
for(int i=0;i<nEndPos.length-1;i++) _xdttO^N
{ ;~s@_}&
nEndPos = nStartPos[i+1]; 73M;-qnU
} EKT"pL-EY
nEndPos[nEndPos.length-1] = nFileLength; b;I!CyD
} Bc#6mO-
} +Jc-9Ko\c;
'`p0T%w
vaZ?>94
//启动子线程 BimM)4g
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; a[gN+DX%L
for(int i=0;i<nStartPos.length;i++) r3.v^
{ qxD<mZ@-R0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D7$xY\0r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;<`
nStartPos,nEndPos,i); iainl@3Qj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (yz8}L3
fileSplitterFetch.start(); `RE1q)o}8M
} j0jam:.p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PvdR)ZEm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Fw;Y)y=O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ..^,*
nEndPos = " + nFileLength); k_Edug~B
// fileSplitterFetch[nPos.length-1].start(); dk2o>jI4;
SiJX5ydz
q}5&B=2pM
//等待子线程结束 PiIILX{DuH
//int count = 0; 0M>%1*
//是否结束while循环 lc0ZfC
boolean breakWhile = false; dnTXx*I:
?rV c}
?Qs>L~
while(!bStop) YCQ+9
{ #D!3a%u0
write_nPos(); fI0L\^b%
Utility.sleep(500); gClDVO
breakWhile = true; [h2V9>4:
@KYmkxW
e3>k"
for(int i=0;i<nStartPos.length;i++) YuDNm}r[
{ ~ .Eln+N
if(!fileSplitterFetch.bDownOver) /h%MWCZWm^
{ oDas~0<oh
breakWhile = false; 8%#uZG\}
break; BF6H_g
} ihhnB
} 3'2}F%!Mv
if(breakWhile) oApI/o
break; l@YpgyqaL
#$%gs]
9/|i.2&
//count++; #Ryu`b
//if(count>4) k07) g:_
// siteStop(); VbX$i!>8
} `o*g2fW!
|wj/lX7y
egi?Qg
System.err.println("文件下载结束！"); Qi7^z;
} `\P:rn95;
catch(Exception e){e.printStackTrace ();} Y<.F/iaH
} D2Go,1
p:ST$1 K
P-`^I`r
//获得文件长度 osX23T~-
public long getFileSize() YKvFZH)
{ I_ .;nU1xA
int nFileLength = -1; A1f]HT
try{ +CNRSq"
URL url = new URL(siteInfoBean.getSSiteURL()); I.e'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a^5`fA/L,
httpConnection.setRequestProperty("User-Agent","NetFox"); E(U}$Zey
ddHIP`wb
qkUr5^1
int responseCode=httpConnection.getResponseCode(); @+X}O/74
if(responseCode>=400) c)E[K-u
{ +msHQk5#$m
processErrorCode(responseCode); |2 wff?
return -2; //-2 represent access is error xD?{Hw>QT#
} ,em6wIq,
pr0V)C6
v|,Hd
String sHeader; '\*Rw]bR|
rrwsj`
TcfBfscU
for(int i=1;;i++) Jp-ae0 Ewa
{ X)f"`$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |f?C*t',
//Utility.log(in.readLine()); *u{.K:.I
sHeader=httpConnection.getHeaderFieldKey(i); 1v\-jM"
if(sHeader!=null) M*S5&xpX
{ fp![Pbms.
if(sHeader.equals("Content-Length")) rw\4KI@ L
{ C aJD*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b);}x1L.T
break; QT&{M #Ydn
} #=.h:_9
} -X}R(.}x
else ,m b3H
break; "^D6%I#T
} NJtB;
} eu:_V+
catch(IOException e){e.printStackTrace ();} ;W*$<~_
catch(Exception e){e.printStackTrace ();} E0DEFB
eXaDx%mM
Rt:PW}rFf
Utility.log(nFileLength); GKd>AP_
6~/H#8Kdn
P*T)/A%4
return nFileLength; )eV40l$ M
} w9PY^U.Y3e
::`j@ ]
GQZUC\cB
//保存下载信息（文件指针位置） J;kbY9e
private void write_nPos() jw[`_
{ 7=AKQ7BB>b
try{ vZDQ@\HrC
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,`7GI*Vq
output.writeInt(nStartPos.length); Cp* n2
for(int i=0;i<nStartPos.length;i++) <C{5(=X{
{ E37@BfpO3
// output.writeLong(nPos); &L?Dogo
output.writeLong(fileSplitterFetch.nStartPos); &sRJ'oc
output.writeLong(fileSplitterFetch.nEndPos); \~H"!vj
} :ZIcWIV-
output.close(); QE}@|H9xs
} 4yM8W\je
catch(IOException e){e.printStackTrace ();} VV4_
catch(Exception e){e.printStackTrace ();} }Tef;8d
} Mvh_>-i
#"M Pe4
*j* WE\
//读取保存的下载信息（文件指针位置） fytx({I .a
private void read_nPos() e](=)h|
{ ,{50zx2
try{ <XagkD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m&%b;%,J
int nCount = input.readInt(); \nyFN
nStartPos = new long[nCount]; bcs!4
nEndPos = new long[nCount]; ~z}au"k
for(int i=0;i<nStartPos.length;i++) !T{g& f
{ S_CtEM
nStartPos = input.readLong(); ^hgAgP{{
nEndPos = input.readLong(); ZkJM?Fzq
} D.6dPzu`
input.close(); xVyUUzXs
} |<*(`\'w
catch(IOException e){e.printStackTrace ();} A!kyga6F5
catch(Exception e){e.printStackTrace ();} Mt Z(\&~
} QBy*y $
D=>^m=?0
jb2:O,+!
private void processErrorCode(int nErrorCode) {\&"I|dpe
{ f)x}_dw%
System.err.println("Error Code : " + nErrorCode); zOOX>3^
} iFA"m;$
*La =7y:
M::iU_
//停止文件下载 #0D.37R+k
public void siteStop() |7$h@KF=S
{ TH!8G,(w
bStop = true; pQY>
for(int i=0;i<nStartPos.length;i++) Q2NnpsA^6
fileSplitterFetch.splitterStop(); 's?Fip
kU/=Du
3>" h*U#
} U;GoC$b}|
} \ c&)8.r
//负责部分文件的抓取 <yPHdbF
**FileSplitterFetch.java ,9qB}HG
*/ SEIu4 l$E
package NetFox; tl5IwrF6;
'[8b0\
:gq@/COo(
import java.io.*; yp^*TD/J
import java.net.*; `W n5 .V
BfT,
88$Y-g5*
public class FileSplitterFetch extends Thread { d6EY'*0
Dj+Osh
&>l8SlC?
String sURL; //File URL ef;L|b%pp
long nStartPos; //File Snippet Start Position N{t:%[
long nEndPos; //File Snippet End Position i_Z5SMZ
int nThreadID; //Thread's ID t`,IW{
boolean bDownOver = false; //Downing is over ZD%_PgiT
boolean bStop = false; //Stop identical YnWl'{[ C
FileAccessI fileAccessI = null; //File Access interface <WJ0St
gj,J3x4TK/
y UAn~!s
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Td1ba^J
{ *v ^"4
this.sURL = sURL; v|(b,J3
this.nStartPos = nStart; O + & xb
this.nEndPos = nEnd; !(K{*7|h
nThreadID = id; b6vYM_ Q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -0da"AB
} oB R(7U~0
MK"
Zw][c7%
public void run() &AcFa<U
{ #L:P R>
while(nStartPos < nEndPos && !bStop) "q^'5p]
{ &vX!7Y
[=6~"!P}
q)ql]iH
try{ ~hslLUE
URL url = new URL(sURL); m8j-lNu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H#6^-6;/
httpConnection.setRequestProperty("User-Agent","NetFox"); .Pes{uHg
String sProperty = "bytes="+nStartPos+"-"; oz6+rM6MY
httpConnection.setRequestProperty("RANGE",sProperty); i:M*L< +
Utility.log(sProperty); .00=U;H%`
Jav2A6a
RIEv*2_O
InputStream input = httpConnection.getInputStream(); 1bZiPG{
//logResponseHead(httpConnection); S<!_ uq
LDEW00zL
`uZv9I"
byte[] b = new byte[1024]; BDkBYhz;7
int nRead; #7-@k-<|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :n9xH
{ KzX ,n_`an
nStartPos += fileAccessI.write(b,0,nRead); =l4\4td9p
//if(nThreadID == 1) iEVA[xy=D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); | 58!A]
} YB B$uGA
G7Abhb,
N@*wi"Q
Utility.log("Thread " + nThreadID + " is over!"); } .3]
bDownOver = true; !x$:8R
//nPos = fileAccessI.write (b,0,nRead); JkDPuTXD
} #;LMtDaL
catch(Exception e){e.printStackTrace ();} L\m!8o4
} <cv2-?L{
} 'gZbNg=&[
H<Kkj
L>Oy7w)Y
//打印回应的头信息 gJ5wAK+?
public void logResponseHead(HttpURLConnection con) bV$8 >[`
{ 'uf2 nUo
for(int i=1;;i++) [j}7@Mr`\
{ xR|eyeR
String header=con.getHeaderFieldKey(i); }d~wDg<#
if(header!=null) '"w}gx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c@9Z&2)
Utility.log(header+" : "+con.getHeaderField(header)); x, Vh
else 4Wla&yy
break; KT];SF^Y
} ]bN&5.|
} ,t%CK!8
?S@R~y0K
}-{b$6]
public void splitterStop() `[@^m5?b-
{ 2rO)qjiH
bStop = true; !jAWNK6
} S*CLt
x\`RW3 K
|rxKCzjm
} mC:X4l]5
nEd M_JPv
u*26>.
/* ]CIQq1iY
**FileAccess.java Ep<!zO|
*//文件访问(定位，写) QP$nDK<
package NetFox; :_^0'ULP
import java.io.*; cK|rrwa0
wrQydI
gHvW e
public class FileAccessI implements Serializable{ abICoP1zQ
,Um5S6 Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 KP=D! l&q
RandomAccessFile oSavedFile; t&R!5^R
long nPos; C|4U78f{
&@4.;u
NokXE
public FileAccessI() throws IOException U~{Sa+
{ gb=80s0
this("",0); YER:ICQ
} ZI58XS+
gH{:`E k7
n5bXQ
public FileAccessI(String sName,long nPos) throws IOException #)_J)/h
{ _8[UtZYG
oSavedFile = new RandomAccessFile(sName,"rw"); M8^.19q;
this.nPos = nPos; b&=]S(
oSavedFile.seek(nPos); 7.Ml9{M/i
} <`c25ih.4
#Rin*HL##
/B,B4JI)/
public synchronized int write(byte[] b,int nStart,int nLen) ?CH?kP
{ 0NQ7#A
int n = -1; {A]k%74-a
try{ 0rku4T
oSavedFile.write(b,nStart,nLen); .Lojzx
n = nLen; c8#T:HM|`
} GFdZ`i
catch(IOException e) ZR/R'prW
{ xw4ey<"I
e.printStackTrace (); m!#_CQ:
} uQ:Qb|
qs!>tw
kF+ZW%6N
return n; ra]!4Kd'
} E7rX1YdR
M0O>Ljo4RN
R(: 4s
} T$H2'tK|
rGTWcJ
3AvVU]@&Z@
/* PqT"jOF]n
**SiteInfoBean.java xik`W!1S
*/ <9@&oN+T
package NetFox; "0|BoG
m9#}X_&x
rW:iBq
public class SiteInfoBean { Ab*]dn`z
]@*tfz\YaH
GS}0;x
private String sSiteURL; //Site's URL oz%h)#;
private String sFilePath; //Saved File's Path /"(b.&
private String sFileName; //Saved File's Name ]KsGkAG
private int nSplitter; //Count of Splited Downloading File 8]My k>
NmjzDN
;xSRwSNDi(
public SiteInfoBean() >4Iv[ D1
{//nSplitter的缺省值为5 N\_( w:q
//default value of nSplitter is 5 "YuZ fL`bb
this("","","",5); clHM8$
} ha_@Yqgh
IK8%Q(.c
L<0=giE
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w3<Z?lj:
{ EtGH\?d~]
sSiteURL= sURL; ?Rlgv5P!
sFilePath = sPath; Y.E?;iS
sFileName = sName; rW[SU:
this.nSplitter = nSpiltter; 'yE*|Sx
`/c7h16
-dg}BM
} u-lrTa""z
*7\W=-
%njOX#.w
public String getSSiteURL() :ezA+=ENg
{ ?hKm&B;d
return sSiteURL; 6%>/og\%
} _~ v-:w
w-lrnjs
^Ss<X}es-
public void setSSiteURL(String value) pNuqT*
{ b<\$d4Qy
sSiteURL = value; {&uT3*V1
} 9 >%+bA(
o5>/}wIf
/n(9&'H<
public String getSFilePath() -=}b;Kf-
{ 1c'79YU
return sFilePath; 5KK{%6#f\
} "rVU4F)
T4eWbNSs
EVG"._I@
public void setSFilePath(String value) `%uK0qw"
{ S:#e8H_7m]
sFilePath = value; 0k%hY{
} 'X54dXS?l
}0Y`|H\v
NJ<N%hcjK
public String getSFileName() `y'aH 'EEd
{ ):S!Nl
return sFileName; 2pz4rc
} $1~c_<DN
)]wuF`
bCzdszvg3
public void setSFileName(String value) 4X*Q6rW
{ Uh*@BmDA
sFileName = value; {f-XyF1`
} )PwQ^||{
+uELTHH=
:v_w!+,/
public int getNSplitter() x=h0Fq,T
{ 4HW;
return nSplitter; )XpVu
} /V#7=,,
#J\s%60pt
dKb ^x^
public void setNSplitter(int nCount) Gh'X.?3
{ f -7S:,
nSplitter = nCount; B_cgWJ*4
} bGu([VB
} 6i| ~7md,
5\&]J7(
};^}2Xo+
/* ]'tJ S]
**Utility.java 4b=Gg
*/ \KCWYi]
package NetFox; lr0M<5d=p
D!S8oKW
^@K WYAAW5
public class Utility { 8]HY. $E
%{U"EZ]D!
5*Btb#:
public Utility() ;7L;
{ 3 &Sp@,
k1RV'
/eb-'m
} !O8.#+
IhfZLE.,
//线程睡眠 D&-vq,c
public static void sleep(int nSecond) i+I0k~wY
{ /~tP7<7A
try{ :s]\k%"
Thread.sleep(nSecond); jccOsG9;_
} %7 /,m
catch(Exception e) ]=|P<F
{ [8TS"ph>
e.printStackTrace (); >P<'L4;
} zC#%6@P\
} 6m@0;Ht
-zdmr"CA
//日志 PV(4$I}
public static void log(String sMsg) z-I|h~ii
{ hVkO%]?
System.err.println(sMsg); [Teh*CV
} >e/ r2U
z>p]/Sa
i&*<lff
public static void log(int sMsg) 50*@.!^*
{ 2eHx"Ha
System.err.println(sMsg); G1/Gq.<
} .zIgbv s
} m &!XA
i?x$w{co
F)7j@h^
/* 9$wAm89
**TestMethod.java ##GY<\",;
*/ {m'AY)
package NetFox; c})wD+1
(2tH"I
},s_nJR:8
public class TestMethod { [[X+P 0`r
%mu>-hac
'-.wFB;
public TestMethod() zIm-X,~I$
{ ///xx/weblogic60b2_win.exe ) $J7sa
try{ W"t"X ~T3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %4/xH9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JRo;(wqZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); N8QH*FX/F1
fileFetch.start(); TaWaHf
} -x5F;d}
catch(Exception e){e.printStackTrace ();} |Qr:!MA
86qcf"?E
3daC;;XO
} :X Lp
2lo:a{}j
|EEi&GOR(y
public static void main(String[] args) }^ ,q#'
{ =JxFp, Xr
new TestMethod(); O"iak
} Sc{Tq\t;%
} (0}j]p'w
点击下载更多相关资料