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)); _+qtH< F/
} V/J-zH&
for(int i=0;i<nEndPos.length-1;i++) 4x" je
{ R'aA\k-
nEndPos = nStartPos[i+1]; bRx}ih
} Bacmrf
nEndPos[nEndPos.length-1] = nFileLength; n;r W
} lv&y<d;
} m!:sDQn{3
=]-D_$S~
uD:tT~
//启动子线程 W 6CNMI]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8[u$CTl7a
for(int i=0;i<nStartPos.length;i++) SOvo%L@
{ uD4$<rSHb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l6-%)6u>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ExSy/^4f
nStartPos,nEndPos,i); 27UnH: =
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :qvaI,
fileSplitterFetch.start(); A )xfO-
} Uy$?B"Z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9j$J}=y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); s5oU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yu=(m~KX
nEndPos = " + nFileLength); Y NGS"3F
// fileSplitterFetch[nPos.length-1].start(); D=~3N
{Pe+d3Eoo
bYy7Ul6]
//等待子线程结束 Bmi9U
//int count = 0; b IZi3GmRF
//是否结束while循环 2%@<A
boolean breakWhile = false; &MGM9 zm-]
g;!,2,De}
CK1gzIg>
while(!bStop) /XwwB
{ jn>RE
write_nPos(); 0zXF{5Up
Utility.sleep(500); ljjnqQ%
breakWhile = true; t<znz6
}E\u2]
u]Dds;~"b
for(int i=0;i<nStartPos.length;i++) tN&X1
{ ;h7O_|<%
if(!fileSplitterFetch.bDownOver) E^t}p[s
{ !{ /AJb
breakWhile = false; G4)X~.Fy
break; e`Tssa+
} O+o_{t\R
} =kn-F T
if(breakWhile) r#WAS2.TP
break; q#.+P1"U
41\V;yib
1lf]}V
//count++; w(nQ:;oC
//if(count>4) Y!AQ7F
// siteStop(); 7)y +QU]
} ]f3R;d
KJ8Qi+cZ
8\CmM\R
System.err.println("文件下载结束！"); :tBZu%N/N
} 4z!(!J)
catch(Exception e){e.printStackTrace ();} [HQ Bx`3TS
} yx/.4DW1Ua
1#^r5E4
n}4Lq^$
//获得文件长度 _u8d`7$*%
public long getFileSize() 1fU~&?&-u
{ '0/[%Q
int nFileLength = -1; 4GqE%n+ta~
try{ ri1:q.:I]
URL url = new URL(siteInfoBean.getSSiteURL()); Iih]q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^|=3sJ4[U
httpConnection.setRequestProperty("User-Agent","NetFox"); 3Uni{Z]Q)
pc/]t^]p
Q#*Pjl
int responseCode=httpConnection.getResponseCode(); %1e{"_$O9
if(responseCode>=400) hOIk6}r4X
{ )n17}Qm`V
processErrorCode(responseCode); "6o5x&H
return -2; //-2 represent access is error C/A~r
} ah0
"QCViR
y7Y g$)sL
String sHeader; %B-m- =gz
f7j9'k
2?\L#=<F
for(int i=1;;i++) "SN+ ^`
{ VtJyE}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); i{6wns?KMj
//Utility.log(in.readLine()); D^\2a;[AxA
sHeader=httpConnection.getHeaderFieldKey(i); 2V=bE-
if(sHeader!=null) ;U$EM+9
{ ]$?\,`
if(sHeader.equals("Content-Length")) f)!7/+9>
{ FK.Qj P:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); P};GcV-
break; \x+"1
} ajALca4
} g'1ASMuR
else \9s x_T
break; RaLc}F)9
} 6T{SRN{
} (Y$48@x
catch(IOException e){e.printStackTrace ();} Shb"Jc_i
catch(Exception e){e.printStackTrace ();} qn|~z@"
};@J)}
DU1\K
Utility.log(nFileLength); P0XVR_TJf
b#E!wMClS
xEvm>BZi
return nFileLength; T&~7*j(|e
} xl;0&/7e
c %.vI
\h 1T/_4
//保存下载信息（文件指针位置） B5fF\N^
private void write_nPos() {>R'IjFc
{ e&J_uG
try{ YUsMq3^&
output = new DataOutputStream(new FileOutputStream(tmpFile)); m kHcGB!~
output.writeInt(nStartPos.length); 3Mt Alc0xp
for(int i=0;i<nStartPos.length;i++) UV8K$n<
{ W05>\Rl
// output.writeLong(nPos); N"rZK/@}
output.writeLong(fileSplitterFetch.nStartPos); (YH/#n1"{
output.writeLong(fileSplitterFetch.nEndPos); (GI]Uyn
} Y+'522er
output.close(); gtV*`g
} zCdzxb_h"
catch(IOException e){e.printStackTrace ();} >gLLr1L\
catch(Exception e){e.printStackTrace ();} N_),'2
} Ig M_l=
<tp#KZE
u.Z,HsEOb
//读取保存的下载信息（文件指针位置） @O%d2bgEWV
private void read_nPos() ;IYH5sG{
{ KK4"H]!.
try{ .WT^L2l%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |8YP8o
int nCount = input.readInt(); a#G]5TZ
nStartPos = new long[nCount]; Ps_q\R
nEndPos = new long[nCount]; Z-B b,8
for(int i=0;i<nStartPos.length;i++) K{x FhdW
{ +Jv*u8T'
nStartPos = input.readLong(); C^hCT
nEndPos = input.readLong(); DRw;.it2
} Oe[qfsdW
input.close(); jJDYl([
} .&Ok53]b
catch(IOException e){e.printStackTrace ();} xRU ~hQ
catch(Exception e){e.printStackTrace ();} yL>wCD,L
} t=Um@;wh
,t=12R]>
ZT'Sw%U:
private void processErrorCode(int nErrorCode) X0"f>.Lg
{ +|=5zWI/
System.err.println("Error Code : " + nErrorCode); 7yK1Q_XY>
} wu2C!gyBo
`Ufv,_n
2>bV+[@B
//停止文件下载 #RA3 T[A
public void siteStop() ~8 w(M
{ M?fRiOj
bStop = true; /K@{(=n
for(int i=0;i<nStartPos.length;i++) }.R].4gT
fileSplitterFetch.splitterStop(); (&a<6k
WgK|r~
:xP$iEA`G
} w(xRL#%
} N2x!RYW
//负责部分文件的抓取 Vt!<.8&`
**FileSplitterFetch.java e;/C}sK:
*/ IAJYD/Y&?
package NetFox; A->y#KQ
ax)j$
:9Vd=M6,
import java.io.*; +e6c4Tw/
import java.net.*; ;dh8|ujh
\O7Vo<B&D
}lzQMT
public class FileSplitterFetch extends Thread { K9J"Q4pEC
fx783
k-LT'>CWl
String sURL; //File URL V^U1o[`
long nStartPos; //File Snippet Start Position i!=28|_
long nEndPos; //File Snippet End Position ?98]\pI
int nThreadID; //Thread's ID Dxwv\+7]
boolean bDownOver = false; //Downing is over U8b1 sz
boolean bStop = false; //Stop identical J '^xDIZX
FileAccessI fileAccessI = null; //File Access interface b:iZ.I
9A4h?/
@-ma_0cZQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /@.c 59r
{ !^|%Z
this.sURL = sURL; VnJ-nfA
this.nStartPos = nStart; vsM] <t
this.nEndPos = nEnd; !j3V'XU#Zn
nThreadID = id; yT>t[t60/S
fileAccessI = new FileAccessI(sName,nStartPos);//定位 L#`9# Q
} v0dFP0.;&
f~.w2Cna
/~LXY<-(
public void run() u%7a&1c
{ hCLXL
while(nStartPos < nEndPos && !bStop) QxGQF|
{ p]zYj >e
i~IQlyGr.
B9Dh^9?L
try{ Qw$"W/&X
URL url = new URL(sURL); r $du-U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FBGHVV w!
httpConnection.setRequestProperty("User-Agent","NetFox"); x,Cc$C~YP
String sProperty = "bytes="+nStartPos+"-"; `FImi9%F
httpConnection.setRequestProperty("RANGE",sProperty); e<>Lr
Utility.log(sProperty); @J~y_J{
G@)I
)6?.; B
InputStream input = httpConnection.getInputStream(); 5g-apod
//logResponseHead(httpConnection); vl@t4\@3
1]@}+H
9@yP;{Q
byte[] b = new byte[1024]; bw7!MAXd
int nRead; LC/w".oq?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) sK:,c5^
{ {I|k@
nStartPos += fileAccessI.write(b,0,nRead); 8i;N|:WdH
//if(nThreadID == 1) v}IP%84
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :*M\z3`k
} ;UgRm#
L-d8bA
0NSn5Hq
Utility.log("Thread " + nThreadID + " is over!"); $p4aNC
bDownOver = true; {zGIQG9
//nPos = fileAccessI.write (b,0,nRead); OvPy+I
} V=|^r?
catch(Exception e){e.printStackTrace ();} >:]fN61#
} xQ7n$.?y@
} K]bS:[34 R
We]X+>BlO
~MY(6P
//打印回应的头信息 cLlfncI
public void logResponseHead(HttpURLConnection con) s\&_Kbw]c
{ Q;P~'
for(int i=1;;i++) &,Q{l$`X
{ fBH&AO$Q
String header=con.getHeaderFieldKey(i); skcMGEB
if(header!=null) R7KQ-+Zb
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (Df<QC`0v
Utility.log(header+" : "+con.getHeaderField(header)); bq4H4?j
else 'w%N(Ntq
break; JMOP/]%D
} 7/vr!tbL`p
} ?E2k]y6<
^BM/K&7^
%:o@IRTRU
public void splitterStop() +^+wS`Y
{ (W/jkm
bStop = true; DuvP3(K
} BH0rT})
MatC2-aV1
BHmA*3?
} W7A'5
4Sg!NPuu7&
cM4?Ggn
/* vP}K(' (
**FileAccess.java oQ;f`JC^
*//文件访问(定位，写) +$>ut r
package NetFox; ):78GVp
import java.io.*; 5 J|;RtcR
gSj-~kP
o33{tUp'
public class FileAccessI implements Serializable{ +lha^){
GIVs)~/Eq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z%/ww7H
RandomAccessFile oSavedFile; !T,7
long nPos; *A\NjXJl~
0HD1Ob^@
ap%o\&T;
public FileAccessI() throws IOException ]bnxOk
{ Y)u}+Yg
this("",0); SbnVU[
} 3}:pD]`h
C6"!'6 W
_z4rx
public FileAccessI(String sName,long nPos) throws IOException K[sM)_I
{ ?XOeMI
oSavedFile = new RandomAccessFile(sName,"rw"); T%a]3
this.nPos = nPos; j|G-9E
oSavedFile.seek(nPos); oZCi_g 5i
} g41Lh3dj
gy =`cMS@
`4EOy:a
public synchronized int write(byte[] b,int nStart,int nLen) z~ u@N9M
{ !RcAJs'
int n = -1; T (2,iG8
try{ Mqh~5NM
oSavedFile.write(b,nStart,nLen); F[=m|MZb
n = nLen; |C&eH$?~=R
} Xi{(1o4%
catch(IOException e) 8&C(0H]1
{ EhFhL4Xdn
e.printStackTrace (); #8z\i2I
} d}o1 j
`f'q/
78QFaN$
return n; ?3Jh{F_+
} }"&(sYQ*`
Ro1' L1:
^,KR0
} FoG<$9
5nj~RUK
b<( W}$x
/* zBs7]z!eP
**SiteInfoBean.java W"-nzdAJ5
*/ KncoIw
package NetFox; 'j)eqoj
D1Sl+NOV
'j3'n0o
public class SiteInfoBean { P~qVr#eU
&"kx(B
0 j.Sb2
private String sSiteURL; //Site's URL JZXc1R| 9
private String sFilePath; //Saved File's Path Ksp;bfe
private String sFileName; //Saved File's Name " }ZD)7K
private int nSplitter; //Count of Splited Downloading File !>:tF,fcB
=5|5j!i=q
j>b OnCp~
public SiteInfoBean() r#Fu<so,
{//nSplitter的缺省值为5 qJ/C*Wqic
//default value of nSplitter is 5 8Cqs@<r4Od
this("","","",5); "|G,P-5G"
} ^]DWrmy
@Hf}PBb
k`AJ$\=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >gSerDH8\
{ ~+np7
sSiteURL= sURL; ".0W8=
sFilePath = sPath; H\k5B_3OU
sFileName = sName; >eTlew<5
this.nSplitter = nSpiltter; CbHNb~
<M7*N.
j%}Jl
} 0@Ijk(|
|d3agfS[n
*Z:PB%d5
public String getSSiteURL() "XY?v8*c
{ +n,BD C;
return sSiteURL; w?tKL0c
} o/zCXZnw#
X2uX+}h*tA
[dJ\|=
public void setSSiteURL(String value) 4r. W:}4:
{ 19.cf3Dh
sSiteURL = value; $;CC lzw
} kUUq9me&o
#~x5}8
*[5
public String getSFilePath() tAA7
{ 5q ,
return sFilePath; cMl%)j-
} vOK;l0%
xB(:d'1|
x]ti3?w
public void setSFilePath(String value) ,2TqzU;
{ Y2X1!Em>B
sFilePath = value; S>,I&`yi
} &FrB6y
9^ r
C'._}\nX
public String getSFileName() iW?9oe
{ JLu0;XVK
return sFileName; Ln_l>X6j51
} j1F+,
%-l:_A
PBL^xlg
public void setSFileName(String value) +_eb*Z`5o
{ xiF%\#N
sFileName = value; )!d1<p3
} s.sy7%{
17cW8\
'u[o`31.
public int getNSplitter() sPg6eAd~?
{ k^pu1g=6I
return nSplitter; >p*HXr|o$
} 42CMRGv
uC(S`Q[Bg
N >!xedw=
public void setNSplitter(int nCount) [bv@qBL
{ 9@Sb! 9h
nSplitter = nCount; %20-^&zZ
} n6G&^Oj
} =BS'oBn^6
XQOprIJ U
SSLshY~d
/* ^qx\e$R
**Utility.java a{*'pY(R0$
*/ Z5Ihc%J^
package NetFox; dCP Tpm
s7o*|Xv
#`4^zU)
public class Utility { t4@g;U?o
6\Vu#r
MNqyEc""
public Utility() g u =fq\`
{ \hW73a!
eH955[fVd4
A9UaLSe
} !>y}Xq{bm3
+)JqEwCrq
//线程睡眠 |u;BAb
public static void sleep(int nSecond) /JeqoM"x
{ W<91m*
try{ &PuJV +y
Thread.sleep(nSecond); 3cO[t\/up
} +g6j=%
catch(Exception e) bM^A9BxD
{ \a2oM$PX
e.printStackTrace (); GFdJFQio
} sK-|xU.
} jL+}F/~r
'uACoME@
//日志 hav?mnVJ
public static void log(String sMsg) N#['fg'
{ ~_db<!a
System.err.println(sMsg); *rz(}(r
} Gd6 ;'ZCmY
7Y|>xx=v
$a*Q).^
public static void log(int sMsg) c9TAV,/fF*
{ D2:a
System.err.println(sMsg); 0aTbzOn&
} G\N"rG=
} 7]xz8t
qm8n7Z/
C.)&FW2F_
/* Bb[e[,ah
**TestMethod.java gDNTIOV
*/ _K}_h\e.
package NetFox; 5m USh3
^xw [d}0S
e1^{
public class TestMethod { Gx_`|I{P
RrU~"P1C
k\&IFSp
public TestMethod() <<On*#80w
{ ///xx/weblogic60b2_win.exe 0S:!Gv+
try{ qVD!/;l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <6b\i5j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {9.~]dI|L
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7R<u=U
fileFetch.start(); Ed&,[rC
} Na 9l#
catch(Exception e){e.printStackTrace ();} $ lsRg:J
h}`&]2|]
Pv %vx U
} KT;C RO>
2@m(XT (
v8[ek@
public static void main(String[] args) b|ksMB>)
{ &Wv`AoV
new TestMethod(); "o#)vA`
} ssX6kgq_(
} @)Hbgkdi
点击下载更多相关资料