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)); v*e=oyx[
} LZ~$=<
for(int i=0;i<nEndPos.length-1;i++) }*0*8~Q'5
{ Yr+ghl/ V
nEndPos = nStartPos[i+1]; +wr 5&
} af7\2g3*
nEndPos[nEndPos.length-1] = nFileLength; ~E7=c3:"
} r+Y]S-o:
} *W<g%j-a
tZY(r {
UBy:W^\g
//启动子线程 8c'E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SbpO<8}8
for(int i=0;i<nStartPos.length;i++) QGd"Z lQ
{ '^M3g-C[Jg
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b*qC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5fa_L'L#
nStartPos,nEndPos,i); {R.@EFkZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *,__\/U98
fileSplitterFetch.start(); ~ +z'pK~c
} eTa[~esu.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [5kaF"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ma26|N5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ag$UNV
nEndPos = " + nFileLength); &+t,fwlM
// fileSplitterFetch[nPos.length-1].start(); F%QVn.
l4Y}<j\;
=zW.~(c{
//等待子线程结束 PfVjfrI[
//int count = 0; )Ikx0vDFQ
//是否结束while循环 ^?tF'l`
boolean breakWhile = false; >U$,/_uMNW
[&FWR
M0%):P?x
while(!bStop) "%Eyb\V!
{ /ZKO\q
write_nPos(); u_U51C\rb
Utility.sleep(500); j^Z3
breakWhile = true; $ p{Q]|ww
H\<C@OkJS}
nZM|8
for(int i=0;i<nStartPos.length;i++) yf7p0;$?
{ sL tsvH#
if(!fileSplitterFetch.bDownOver) SNd]c
{ SuW_[6]
breakWhile = false; 1)M>vdrP
break; Ye_)~,{,p
} 5ff66CRw
} # 1,(I
if(breakWhile) asI:J/%+2
break; 4o2C=?@(
=jmn
ghiFI<)VY
//count++; wLC|mByq
//if(count>4) rT ~qoA\
// siteStop(); u]ZCYJ>
} @cF aYI
N*My2t_+E
B9^@]
System.err.println("文件下载结束！"); Jj'~\j
} *(x`cf;k
catch(Exception e){e.printStackTrace ();} l+Tw#2s$
} ^@`dsll
HtIM8z#/
/5_!Y>W
//获得文件长度 RxkcQL/Le
public long getFileSize() c>r0N[
{ @&2bLJJ+
int nFileLength = -1; j=d@Ih*
try{ eW+z@\d9Gz
URL url = new URL(siteInfoBean.getSSiteURL()); ZuF-$]oL&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BfF$
httpConnection.setRequestProperty("User-Agent","NetFox"); F/}PN1#T
jfHVXu^M
' 7>V4\"
int responseCode=httpConnection.getResponseCode(); PhM3?$
if(responseCode>=400) |k> _ jO
{ :nw4K(:f
processErrorCode(responseCode); avk0pY(n
return -2; //-2 represent access is error Z%MP:@z
} y)!K@
-q\1Tlc]3
BaTE59W
String sHeader; 3%xj-7z W
SVaC)O(
*A O/$K@Ma
for(int i=1;;i++) (_E<?
{ [HK[{M=v=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `hL16S
//Utility.log(in.readLine()); xq.,7#3
sHeader=httpConnection.getHeaderFieldKey(i); t8 #&bUX
if(sHeader!=null) y#^d8 }+
{ +X0?bVT
if(sHeader.equals("Content-Length")) HkEfBQmh
{ 4jj@"*^a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5B@+$D[0?3
break; .QzHHW4&0
} Z@ *^4Ve
} W[: n*h
else ~(%nnG6x
break; z6b!,lp
} N%:QaCZKw
} Ylll4w62N
catch(IOException e){e.printStackTrace ();} BYrj#n5
catch(Exception e){e.printStackTrace ();} y}5H<ZcXA
< ppg$;
>c?Z.of
Utility.log(nFileLength); F%t`dz!L
y'pAhdF
kl_JJX6jPP
return nFileLength; DnP>ed"M!
} a&p|>,WS
tD.md_E
|28z4.
//保存下载信息（文件指针位置） $+)SW{7
private void write_nPos() [F/>pL5U$
{ gEMxK2MNXj
try{ {?17Zth
output = new DataOutputStream(new FileOutputStream(tmpFile)); :03w k)
output.writeInt(nStartPos.length); ^N _kiSr
for(int i=0;i<nStartPos.length;i++) 6+e@)[l.zc
{ dmW0SK
// output.writeLong(nPos); )VID ;l;4
output.writeLong(fileSplitterFetch.nStartPos); B_anO{3$4
output.writeLong(fileSplitterFetch.nEndPos); &%}6&PWi
} iZB?5|*
output.close(); S v$%-x^t
} *f=H#
catch(IOException e){e.printStackTrace ();} 1j "/}0fx
catch(Exception e){e.printStackTrace ();} I1S*=^Z_U
} DDyeNuK
V.6h6B!vB
p@y?xZS
//读取保存的下载信息（文件指针位置） %:sQ[^0
private void read_nPos() DZ |0CB~
{ +dcBh Dq
try{ >fPa>[_1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9"KEHf!
int nCount = input.readInt(); +ZEj(fd9
nStartPos = new long[nCount]; <T+)~&g$
nEndPos = new long[nCount]; YN#i^(
for(int i=0;i<nStartPos.length;i++) De@GNN"-
{ ,8nu%zcVn
nStartPos = input.readLong(); |?hNl2m
nEndPos = input.readLong(); F$7>q'#
} i<l_z&
input.close(); K2<"O qp_W
} 7,ysixY
catch(IOException e){e.printStackTrace ();} 9^,MC&eb
catch(Exception e){e.printStackTrace ();} V)72]p
} j BS$xW
Q\z6/1:9Z
fwK5p?Xhm
private void processErrorCode(int nErrorCode) t23uQR#>b_
{ D |kdk;Xv
System.err.println("Error Code : " + nErrorCode); EaaQC]/OX5
} 85+'9#~!
_SC{nZ[
)HQ':ZE$
//停止文件下载 -'r4@='6}
public void siteStop() :3J,t//c
{ @9lV~,,U
bStop = true; U,Ya^2h%
for(int i=0;i<nStartPos.length;i++) (pN:ETB
fileSplitterFetch.splitterStop(); O%L]*vIr
VAX@'iZr
"`qmeZ$rg
} awkPFA*c'
} >M=_:52.+
//负责部分文件的抓取 3oc p4x`[
**FileSplitterFetch.java E1IT>_
*/ Ybo:2e
package NetFox; ce@1#}*
}W^%5o87{
vVQwuV
import java.io.*; \!M6-kmi
import java.net.*; r#rL~Rsd}
;c p*]
'c7C*6;a
public class FileSplitterFetch extends Thread { /k8Lu+OJ
.}!"J`{W
Z"j #kaXA
String sURL; //File URL p5`iq~e9
long nStartPos; //File Snippet Start Position LK\L}<;1V
long nEndPos; //File Snippet End Position yuIy?K
int nThreadID; //Thread's ID Cw6\'p%l-\
boolean bDownOver = false; //Downing is over @oE^(
boolean bStop = false; //Stop identical D1hy:KkAv]
FileAccessI fileAccessI = null; //File Access interface .8Eh[yiln
3,`I\>No
vZMb/}-o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;Z^\$v9?
{ N~H!6N W
this.sURL = sURL; B'}h6ZH
this.nStartPos = nStart; 9U~fc U6
this.nEndPos = nEnd; U )kl!
nThreadID = id; >T84NFdz+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Nz/PAs7g6
} JBqL0H
U'~M(9uv:
J5dwd,FQ
public void run() skrdL.5
{ by07l5
while(nStartPos < nEndPos && !bStop) uCkXzb9_z
{ S7pf QF
AXnRAW
CjR!dh1w_
try{ eX)'C>4W
URL url = new URL(sURL); u}I-#j)wap
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O-P'Ff"}t
httpConnection.setRequestProperty("User-Agent","NetFox"); Td,2.YMQ
String sProperty = "bytes="+nStartPos+"-"; zF: :?L~
httpConnection.setRequestProperty("RANGE",sProperty); M%&1j >d
Utility.log(sProperty); EzII!0 F
0?V{u`*
0zQ~'x
InputStream input = httpConnection.getInputStream(); mIW8K ):
//logResponseHead(httpConnection); 75v7w
N+lhztYQ?
DVJuX~'|!
byte[] b = new byte[1024]; gq%U5J"x;J
int nRead; ?D>%+rK8c
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `JQw]\f4>
{ i~Qnw-^B
nStartPos += fileAccessI.write(b,0,nRead); UHyGW$B
//if(nThreadID == 1) /{6&99SJcc
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &t)$5\r
} jVlXB6[-
,~Y[XazT
]@Z[/z%~04
Utility.log("Thread " + nThreadID + " is over!"); r:{;HM+
bDownOver = true; oYx4+xH/
//nPos = fileAccessI.write (b,0,nRead); ?)NgODU
} [0bp1S~
catch(Exception e){e.printStackTrace ();} ._%8H
} Jb/VITqN4
} @LSfP
B:)PUBb
P5Bva
//打印回应的头信息 G*s5GG@Z.
public void logResponseHead(HttpURLConnection con) SI`ems{1>c
{ vVhSl$mW
for(int i=1;;i++) mzO5&h7
{ CwjKz*'[g
String header=con.getHeaderFieldKey(i); i[Qq,MmC
if(header!=null) / jLb{Ky
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]hMs:$}
Utility.log(header+" : "+con.getHeaderField(header)); xs 1V?0
else B_DyH C\<
break; h ?_@nQ!
} xiv8q/
} Vp$<@Y
/np05XhEa
G^ShN45
public void splitterStop() :(Ak:
{ HXm&`
bStop = true; ppuJC'GW
} "]T1DG"
a#D \8;
+ L[a
} ?`= <*{_o
~%eZQgqA*
c( _R xLJ
/* :W.pD:/=v
**FileAccess.java RH9P$;.7
*//文件访问(定位，写) \E {'|
package NetFox; $~e55X'!+
import java.io.*; ? KDg|d
`3eQ#,G!
"M;[c9
public class FileAccessI implements Serializable{ &t U&ZH
{3T&6LA
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z? Iu;X
RandomAccessFile oSavedFile; s .@Szq
long nPos; qXprD.; }
Ip<~Y
sFPh?
public FileAccessI() throws IOException v}5||s!=
{ U:AB%gr[
this("",0); TH"<6*f2L
} ug_c}Nv=Y
i,zZJ=a$
nt%fJ k
public FileAccessI(String sName,long nPos) throws IOException /2Z7
{ a|5<L
oSavedFile = new RandomAccessFile(sName,"rw"); O]XgA0]
this.nPos = nPos; T|&u?
oSavedFile.seek(nPos); PYwGGB-
} :IO"' b
lDL(,ZZS`
~\*wt(o
public synchronized int write(byte[] b,int nStart,int nLen) '%&-`/x
{ SB|Cr:wM
int n = -1; ! o?E.
try{ 4d_Az'7`4
oSavedFile.write(b,nStart,nLen); $azK M,<q
n = nLen; EK Ac>g
} \'r;1W
catch(IOException e) %+((F+[
{ 2K^xN]]rG
e.printStackTrace (); B qo#cnlG
} G%junS'zt
as73/J6
ujn7DBE"
return n; 6P T)
} a$EudD#+
r]'[qaP
]5Q)mWF
} CD. XZA[
wHZ(=z/q
kT%m`
/* fo=@ X>S
**SiteInfoBean.java pxI[/vS N
*/ }R~C<3u\2
package NetFox; og1Cj{0
RT2&^9-
- i{1h"
public class SiteInfoBean { ac,<+y7A
j*FpQiBoT
i!G<sfL
private String sSiteURL; //Site's URL O))j
private String sFilePath; //Saved File's Path T4J WZ
private String sFileName; //Saved File's Name N3V4Mpf
private int nSplitter; //Count of Splited Downloading File ]M 2n%9
#<@_mbQ@|K
UhXVeGO
public SiteInfoBean() <'jygZ(
{//nSplitter的缺省值为5 #sv:)p
//default value of nSplitter is 5 J[UTn'M8]
this("","","",5); g2vt(Gf;
} mC$te
?es9j]
/VFQbJ+`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |}: D_TX
{ [fJxbr"
sSiteURL= sURL; +jN)$Y3Ya
sFilePath = sPath; Bnz}:te}
sFileName = sName; gF]IAZCi
this.nSplitter = nSpiltter; P@<K&S+f
" ;o,D
@7sHFwtar?
} ,D.@6bJW
2h)*
OTEx9
public String getSSiteURL() j'XND`3
{ w[uwhd
return sSiteURL; SbobXTbG
} Wt=%.Y(x
SwO8d;e
BOl*. t
public void setSSiteURL(String value) P#/s5D8
{ sDwE,f0h
sSiteURL = value; z-|d/#h
} 2{G7ignv
aw3rTT(
R_IT${O
public String getSFilePath() wh3Wuh?x
{ h m(
return sFilePath; $wcV~'fM
} 9Z:pss@
W,%qL6qV
zB"y^g
public void setSFilePath(String value) 3P*"$fH
{ rY"EW"y
sFilePath = value; 'l1cuAP!+
} InG<B,/W?
^Uldyv/
K&&YxX~3
public String getSFileName() ]2z Gb5s"
{ NV^n}]ci
return sFileName; ?o d*"M
} 1!R:}r3t
QjsN7h&%
pS!N<;OWr
public void setSFileName(String value) b~+\\,q}
{ 2!a~YT
sFileName = value; \qbEC.-K
} "; ?^gA
XE|"n
tTe:Oq
public int getNSplitter() k")3R}mX
{ )1&,khd/u
return nSplitter; SU4~x0
} AH ]L C6-
8=3$U+
-<5H8P-
public void setNSplitter(int nCount) d`KW]HJw
{ ={nuz-3
nSplitter = nCount; -:V2Dsr6;
} f q*V76F
} 68!=`49r>
Z15b'^)?9
4hV~ ir
/* ulXe;2
**Utility.java KkZo|\V
*/ D]Gt=2\NG9
package NetFox; MLn?t^v-
G]I^zd&P
?tYc2R9x6"
public class Utility { R(A"6a8*
!xD_=O
28o!>*
public Utility() O:X|/g0Y
{ wk6tdY{&s
u=B,i#>s
4Bq4d.0
} .w~zW*M0
,:3Di (
//线程睡眠 MtK5>mhZI`
public static void sleep(int nSecond) -MeO|HWm
{ 0Yc#fD
try{ JZ0u/x5
Thread.sleep(nSecond); 9/50+2F
} TGozoPV
catch(Exception e) 86f/R c
{ yl~h `b4
e.printStackTrace (); $g)X,iQu
} qgsKbsl
} a.g:yWL\
-\fn\n
//日志 }MV=t7x9+
public static void log(String sMsg) rxAb]~MMp
{ n5 jzVv
System.err.println(sMsg); y:8Oc?
} z,=k F I
.JL?RH2@8
`@i!'h
public static void log(int sMsg) @&]%%o+
{ Qtn%h:i S~
System.err.println(sMsg); 2aO.t
} :S{+|4pH
} [y$sJF7;I
TfqQh!Y
?!kPW^gD
/* eMDraJv@
**TestMethod.java m-!Uy$yM
*/ [?Q$b5j/M
package NetFox; NX:i]t
s:#\U!>0`
/CN`U7:E
public class TestMethod { [P746b_\e
)}jXC4
Az>gaJ/_
public TestMethod() 8_F5c@7
{ ///xx/weblogic60b2_win.exe 69u"/7X
try{ #Y9~ Xp^.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \LpR7D
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Kdwt^8Umh
SiteFileFetch fileFetch = new SiteFileFetch(bean); X Sw0t8
fileFetch.start(); 2Fsv_t&*>
} 4q\bnt
catch(Exception e){e.printStackTrace ();} l>O~^41[
r+%}XS%;h
X,8]g.<
} J-g<-!>RM
myeez+@ m
Th)Z?\8zk
public static void main(String[] args) /<$\)|r
{ &*N;yW""f
new TestMethod(); F"Y.'my8
} Sq,x57-
} Cl5l+I\1
点击下载更多相关资料