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)); B5>1T[T'-
} >^#OtFHuT)
for(int i=0;i<nEndPos.length-1;i++) "T/ vE
{ 289@O-
nEndPos = nStartPos[i+1]; jXEuK:exQ
} Lw 7,[?,Z
nEndPos[nEndPos.length-1] = nFileLength; |sN>/89=/
} [E_eaez7#
} ~+1t3M e
-jc8ku3*
(3YI>/#
//启动子线程 ;\@co5.=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; olNgtSX
for(int i=0;i<nStartPos.length;i++) T~%}(0=m
{ ), >jBYMJ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3siWq9.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @V/Lqia
nStartPos,nEndPos,i); ;2||g8'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -c-#1_X5
fileSplitterFetch.start(); C WJGr:}&
} En:.U9?X
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bkQEfx.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \ltA&}!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [|ghq
nEndPos = " + nFileLength); 2IgTB|2
// fileSplitterFetch[nPos.length-1].start(); D-8NDa(`
P"dWh;I_
5"4O_JQ
//等待子线程结束 ?*i qg[:
//int count = 0; bT|NZ!V
//是否结束while循环 I#0WN
boolean breakWhile = false; j9zK=eG
I g/SaEF
p`// *gl
while(!bStop) Byf5~OC
{ pyEi@L1p
write_nPos(); T:ye2yg
Utility.sleep(500); -aCtk$3
breakWhile = true; d'~sy>
Cx$M
<szD"p|K
for(int i=0;i<nStartPos.length;i++) 6fvzTd},
{ >hcA:\UPk
if(!fileSplitterFetch.bDownOver) VeixwGZ.
{ c[:OK9TH
breakWhile = false; SG1o<#>
break; >[ r TUn;
} aa8xo5tIp
} (fmcWHs
if(breakWhile) s;'XX}Y
break; Qe=,EXf
k!e \O>+
N zY}-:{
//count++; I^iJ^Z]vx
//if(count>4) F+A"-k_\T#
// siteStop(); X {,OP/
} PI>PEge!&
@5n!t1(
Kq}/`P
System.err.println("文件下载结束！"); shbPy
} Nz`4q%+
catch(Exception e){e.printStackTrace ();} S<"M5e
} nQuiRTU<
b#U nE
vn"2"hPF|
//获得文件长度 8spoDb.S
public long getFileSize() pkjf5DWp
{ I@VhxJh
int nFileLength = -1; iB[>uW
try{ }mRus<Ax
URL url = new URL(siteInfoBean.getSSiteURL()); > Y <in/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `ReTfz;o
httpConnection.setRequestProperty("User-Agent","NetFox"); xaO9?{O
TJ@@kSSbl
3F'{JP
int responseCode=httpConnection.getResponseCode(); rzJNHf=FVY
if(responseCode>=400) QUL^]6$
{ @OOnO+g
processErrorCode(responseCode); %c%0pGn8-
return -2; //-2 represent access is error =[8EQdR
} BZy&;P
VeO$n*O
3w9j~s
String sHeader; ?bc-?<Xk
)X{x\ /N
Fy|tKMhnc
for(int i=1;;i++) T9r"vw
{ -"qw5Y_oF?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7;dTQ.%n
//Utility.log(in.readLine()); Fj\}&H*+
sHeader=httpConnection.getHeaderFieldKey(i); %,$Ms?,n`
if(sHeader!=null) 7a_pO1MBL
{ |;2Y|>=
if(sHeader.equals("Content-Length")) {UpHHH:X#
{ -<kl d+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2Y_ `&
break; VuqN)CE^Uq
} OU;R;=/]
} >$,A [|R
else /C(lQs*l
break; .'o<.\R8
} h&eu}aF
} !@mV$nTA
catch(IOException e){e.printStackTrace ();} dkTj KV
catch(Exception e){e.printStackTrace ();} z-|gw.y
pKDP1S#<
sBP.P7u
Utility.log(nFileLength); ok;Yxp>
M<Mr L[*j
( zQ)EHRD
return nFileLength; [:gPp)f,
} NpV#zzE
(Fq|hgOA>M
HRkO.230
//保存下载信息（文件指针位置） ^)ouL25Z*2
private void write_nPos() E"!I[
{ yM$@*od
try{ ~=hM y`Ml
output = new DataOutputStream(new FileOutputStream(tmpFile)); CJB
output.writeInt(nStartPos.length); V4cCu~(3;~
for(int i=0;i<nStartPos.length;i++) [+0rlmB
{ Va^Y3/
// output.writeLong(nPos); Z;kRQ
output.writeLong(fileSplitterFetch.nStartPos); V@gweci
output.writeLong(fileSplitterFetch.nEndPos); F"2v5F@
} mdxa^#w
output.close(); 1e`/N+6u
} Df;EemCh
catch(IOException e){e.printStackTrace ();} >|%dN jf@Q
catch(Exception e){e.printStackTrace ();} RUcpdeo
} /]H6'
"]M:+mH{]
n%;wQ^
//读取保存的下载信息（文件指针位置） c$?(zt;
private void read_nPos() PW(4-H
{ 1iWo*+5
try{ f%n],tE6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o>rsk 6lNi
int nCount = input.readInt(); Jy&O4g/'5
nStartPos = new long[nCount]; [{.e1s<EK
nEndPos = new long[nCount]; XWH{+c"
for(int i=0;i<nStartPos.length;i++) Il(p!l<Xz#
{ 5W/!o&x~7
nStartPos = input.readLong(); _`yd"0Ux
nEndPos = input.readLong(); pME17 af
} ZH8O%>!
input.close(); yOKpi&! r
} shjc`Tqm
catch(IOException e){e.printStackTrace ();} 5\RTy}w3x
catch(Exception e){e.printStackTrace ();} L:$kd `v[
} KT1/PWa
qEvHrsw},
Rh!B4oB4
private void processErrorCode(int nErrorCode) MfNxd 6w
{ \]Nlka
System.err.println("Error Code : " + nErrorCode); VC%{qal;q
} C!KxY/*Px
>B)&mC$$S
R`}C/'Ty
//停止文件下载 7_Yxz$m
public void siteStop() I&9_F%rX
{ "YU<CO;4VV
bStop = true; 8bQ\7jb
for(int i=0;i<nStartPos.length;i++) "`P/j+-rt
fileSplitterFetch.splitterStop(); `#O%ZZ+
ML6Y_|6 |
O$QtZE61
} U5X\RXy~
} lJaR,,
//负责部分文件的抓取 j`JY3RDD
**FileSplitterFetch.java W;~ f865
*/ Dqss/vwV
package NetFox; %@/"BF;r
sywSvnPuYZ
Hc?8Q\O:
import java.io.*; A-5xgp,
import java.net.*; /Y=Cg%+
<A{|=2<
!cP2,l'f
public class FileSplitterFetch extends Thread { ^)$(Fe<
>*jcXao^
eVL#3|=
String sURL; //File URL ${(v Er#}k
long nStartPos; //File Snippet Start Position -$W#bqvz^
long nEndPos; //File Snippet End Position Co|3k:I 8
int nThreadID; //Thread's ID uTsxSkHb/
boolean bDownOver = false; //Downing is over s"u6po.'
boolean bStop = false; //Stop identical Z(Styn/x
FileAccessI fileAccessI = null; //File Access interface a?Q\nu1
W+HiH`Qb]
K9{3,!1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aYTVYg
{ ^L}ICm_#
this.sURL = sURL; a]0B{
this.nStartPos = nStart; bf1Tky=/
this.nEndPos = nEnd; ODvlix
nThreadID = id; U^qQ((ek
fileAccessI = new FileAccessI(sName,nStartPos);//定位 GyU9,>|~T
} XO[S(q
r\#_b4-v3h
ZJL8"(/R
public void run() -Jqm0)2
{ BE,XiH;
while(nStartPos < nEndPos && !bStop) ?`9XFE~a!
{ m\9R;$\
yV{&x
|.w'Z7(s
try{ _+c' z
URL url = new URL(sURL); Be~__pd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nV/8u_
httpConnection.setRequestProperty("User-Agent","NetFox"); zKRt\;PW
String sProperty = "bytes="+nStartPos+"-"; Ew`(x30E
httpConnection.setRequestProperty("RANGE",sProperty); r~mZ?dI
Utility.log(sProperty); ;<=Z\NX
@bPR"j5D
/j7e q
InputStream input = httpConnection.getInputStream(); >"LHr&;m&h
//logResponseHead(httpConnection); ^HS;\8Xvb
:P,g,
L7kNQ/
byte[] b = new byte[1024]; 4XL$I*;4
int nRead; zL8Z8eh">
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G =`-w
{ k2bjBAT
nStartPos += fileAccessI.write(b,0,nRead); ^?+qNbK
//if(nThreadID == 1) ]~a;tF>Fw
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7j,-o
} kSW=DE|#}
PjwDth A1
}~I(e
Utility.log("Thread " + nThreadID + " is over!"); HgGwV;W
bDownOver = true; =g.R?H8cj5
//nPos = fileAccessI.write (b,0,nRead); fL xGaOT
} h#hx(5"6
catch(Exception e){e.printStackTrace ();} 9Wu c1#
} tLH:'"{zx
} _\/KI /
K#"J8h;x
CdEQiu
//打印回应的头信息 LDDgg u
public void logResponseHead(HttpURLConnection con) &7\=Jw7w
{ W8blHw"
for(int i=1;;i++) lF[m*}l
{ 5taR[ukM
String header=con.getHeaderFieldKey(i); rCK
if(header!=null) XC(:O(jdA2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]!c59%f=
Utility.log(header+" : "+con.getHeaderField(header)); }4uHT.)
else /b1+ ^|_
break; "U"phLX
} }}Zwdpo
} -gQtw% `x
3# g"Z7/
bIXudE[8zq
public void splitterStop() c;X%Ar
{ f]pHJVgFV
bStop = true; #ORZk6e
} @=7[KMb
"L0Q"t:
C6?({ QB@
} @Ojbu@A
zb]e{$q2C
*M?[Gro/
/* -lY,lC>{
**FileAccess.java 70GwTK.{~
*//文件访问(定位，写) %jE0Z4\
package NetFox; &ir|2"HV
import java.io.*; I[6ft_*
dEhFuNO<2
#0"Pd8@
public class FileAccessI implements Serializable{ lC=-1*WH
\y(ZeNs
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4<j7F4
RandomAccessFile oSavedFile; 2/iBk'd
long nPos; &At9@
[;C|WTYSL
y$}o{VE{x
public FileAccessI() throws IOException | |u
{ [t6Y,yo&h4
this("",0); ^, &'
} &s(mbpV
3Q#Tut
j0b>n#e7
public FileAccessI(String sName,long nPos) throws IOException #AR$'TE#
{ S"cim\9xP
oSavedFile = new RandomAccessFile(sName,"rw"); {.j030Q
this.nPos = nPos; S l`F`
oSavedFile.seek(nPos); FvJkb!5*e_
} G@3Jw[t
&R))c|>OT&
-l~+cI\2
public synchronized int write(byte[] b,int nStart,int nLen) NI:3hfs
{ ]&?8l:3-G
int n = -1; 9'=ZxV
try{ "$nff=]
oSavedFile.write(b,nStart,nLen); c :2w(BVi
n = nLen; &X6hOc:``\
} =3Ohy,5L
catch(IOException e) `< 82"cAT{
{ #=T^XHjQ
e.printStackTrace (); [VE>{4]W
} z[qi~&7:v
m@W>ku
]P96-x
return n; r+usMF<'
} \iA.{,VX
Nwg?(h#
[NK&s:wMk
} `n"PHur
uE}$ZBiq
e0M'\'J
/* A[`2Mnj
**SiteInfoBean.java oL7F^34;
*/ IQWoK"B
package NetFox; X4JSI%E
*LEI@
)S`=y-L$
public class SiteInfoBean { M0t9`Z9
0_N.s5~N
lf\^!E:
private String sSiteURL; //Site's URL D?G'1+RIT~
private String sFilePath; //Saved File's Path +q%b'!&Q
private String sFileName; //Saved File's Name (W.G&VSn)
private int nSplitter; //Count of Splited Downloading File ')TS'p,n
Fd#Zu.Np
Ab8Ke|fA
public SiteInfoBean() lMgPwvs'
{//nSplitter的缺省值为5 m86ztP)
//default value of nSplitter is 5 Y(Y#H$w
this("","","",5); vwzElZ{C:v
} +(Jh$b_
yG^pND>_df
#itZ~tol
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V@nZ_.
{ * ).YU[i
sSiteURL= sURL; ;u=%Vn"2a
sFilePath = sPath; !AG {`[b
sFileName = sName; MS]Q\g}U
this.nSplitter = nSpiltter; 72vp6/;)
JL[!8NyU
+~sqv?8
} Yq'D-$@
vSY YetL
4HpKKhv"
public String getSSiteURL() J06D_'{
{ W![~"7?
return sSiteURL; A1*\ \[
} :x3xeVtY
{&a6<y#-
y&V'GhW!dd
public void setSSiteURL(String value) ?Iu=os>*
{ &}t8O?!
sSiteURL = value; !3{;oU%*
} |D_4 iFC
j<k-w
#N;&^El
public String getSFilePath() :? s{@7
{ &Mz]y?k'
return sFilePath; Cu_-QE
} /.~zk(-&h
v3G$9(NE;
pK ^$^*#
public void setSFilePath(String value) sY1.z5"Mm
{ L2wX?NA
sFilePath = value; -!V{wD3,B
} uL~wMX
C;%dZ
2XEE/]^
public String getSFileName() g+7j?vC{'
{ TF80WMt
return sFileName; q,> C^p|2b
} 4$81ilBcL
4aW[`
xSDTO$U8%
public void setSFileName(String value) saDu'SmYV
{ `xZ,*G7(*
sFileName = value; a!f71k r
} :F9Oj1lM%
4P"XT
X<5&R{oZ
public int getNSplitter() 3E0C$vKM
{ oS}fr?
return nSplitter; 0JKTwLhC
} CNhLp#
6G}4KGQc
A~^x*#q{4
public void setNSplitter(int nCount) ^8YBW<9
{ j WMTQLE.
nSplitter = nCount; dpX Fx"4A
} eNO[ikm
} !Rgj'{
@%YbptT}
i29a1nD4Hm
/* [)kuu
**Utility.java $=`d[04
*/ m&z(2yb1
package NetFox; LFZ*mRiuKE
REh\WgV!u
z`NJelcuz\
public class Utility { )eqF21\
S<-5<Pg
E25w^x2
public Utility() G}LV"0?
{ 1Dhu5ht
b`%!\I
RKM5FXX
} )vpYVr-
#sk~L21A
//线程睡眠 a*:GCGe
public static void sleep(int nSecond) {oR@'^N
{ u} +?'B)
try{ h%NM%;"H/
Thread.sleep(nSecond); Jr= fc*f
} ZHlHnUo
catch(Exception e) bTZ.y.sI
{ p L^3*B.Nr
e.printStackTrace (); #{^qBP[
} 6eA)d#
} YU!s;h
GV28&!4sS
//日志 |sl^4'Ghc
public static void log(String sMsg) _ n1:v~
{ 8j :=D!S
System.err.println(sMsg); ?;.=o?e9
} 2;J\Z=7
SU6Aq?`@
SJlE!MK
public static void log(int sMsg) n3qRt
{ )[r=(6?n
System.err.println(sMsg); p=zTY7L
} g}uSIv^
} s&<76kwl
Y>ATL
{,Rlq
/* DL,]iJm
**TestMethod.java lC,~_Yb
*/ ll- KK`Ka
package NetFox; u8`S*i/)m
& 9 c^9<F
UI%4d3
public class TestMethod { zA:q/i
x25zk4-
;sqxFF@
public TestMethod() Yx,7e(AI`
{ ///xx/weblogic60b2_win.exe 9_e_Ne`i`?
try{ (0.JoeA`y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s.n:;8RibP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bD|"c
SiteFileFetch fileFetch = new SiteFileFetch(bean); |F<%gJ
fileFetch.start(); @Y>PtA&w*
} 1<MJ3"60
catch(Exception e){e.printStackTrace ();} Zk>m!F>,p
ccp9nXv
inZ0iU9dy
} 01uj-!D$@
z"QXPIXPk
W}}ZP];
public static void main(String[] args) &^uaoB0
{ s0/m qZ]s
new TestMethod(); a"T+CA
} Aayd3Ph0%
} g)D@4RM
点击下载更多相关资料