http断点续传简单实现（java)

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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)); {_toh/8)r
} +V);'"L
for(int i=0;i<nEndPos.length-1;i++) A6UdWK
{ 5Jhbf2-
nEndPos = nStartPos[i+1]; opcR~tg@r
} 56=K@$L {F
nEndPos[nEndPos.length-1] = nFileLength; akvwApn5
} SeNF!k% Y
} ;Ma/b=Y
Pm#x?1rAj
(\mulj
//启动子线程 g"!#]LLe
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @>#{WI:"~
for(int i=0;i<nStartPos.length;i++) "gbnLKs
{ T7lj39pJq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j*H;a ?Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), XAU_SPAjiw
nStartPos,nEndPos,i); 7Z`Mt9:Ht
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V3 _b!
fileSplitterFetch.start(); <5ft6a2fQ
} [Zt# c C+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gN, k/U8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TvWU[=4Yk
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pqH( Tbjq
nEndPos = " + nFileLength); Q k;Kn
// fileSplitterFetch[nPos.length-1].start(); cbh#E)['
AFINm%\/0
{8{t]LK<
//等待子线程结束 }c35FM,
//int count = 0; a81!~1A
//是否结束while循环 cZaF f?]k
boolean breakWhile = false; 3b|7[7}&
'Vm5Cs$
OAW=Pozr9
while(!bStop) ?z5ne??
{ rw5#e.~V
write_nPos(); `i t+D
Utility.sleep(500); SaR}\Up
breakWhile = true; waXDGdl0
Q\o$**+{
5Cc6, ]
for(int i=0;i<nStartPos.length;i++) .K|P&
{ dysX
if(!fileSplitterFetch.bDownOver) H5AK n*'7
{ $ DDSN
breakWhile = false; 6K4`;
break; x1m8~F
} Kf05<J!
} uQ:ut(
if(breakWhile) ub`z7gL
break; j*;*Ka w
7y>Tn`V8G
rPiiC/T.`
//count++; j<l#qho{h
//if(count>4) ->&BcPLn
// siteStop(); }.fL$,7a
} _l#3]#
|`_ <@b
kf+JM/
System.err.println("文件下载结束！"); q4sl=`L5Sp
} ",~ b2]ym
catch(Exception e){e.printStackTrace ();} U;';"9C2>
} 457fT|
nmD1C_&
(@%XWg
//获得文件长度 eZ!yPdgy|
public long getFileSize() uIYcmF\?
{ 5wzQ?07T_
int nFileLength = -1; q?;N7P
try{ 8`:M\*
URL url = new URL(siteInfoBean.getSSiteURL()); "t5 +*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]{K5zSK
httpConnection.setRequestProperty("User-Agent","NetFox"); wD<vg3e[H
(y=dR1p
_wm~}_Q
int responseCode=httpConnection.getResponseCode(); 'fS?xDs-v
if(responseCode>=400) ,(j>)g2Ob
{ J*}VV9H
processErrorCode(responseCode); v$t{o{3
return -2; //-2 represent access is error m3U+ du
} o{9?:*?7
l*QIoRYFW
!(B_EM
String sHeader; CHPL>'NJzc
bHO7*E
hX0RET
for(int i=1;;i++) D8k*0ei&
{ (3AYy0J%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jZa25Z00
//Utility.log(in.readLine()); @ L\-ZWq
sHeader=httpConnection.getHeaderFieldKey(i); sk#9x`Rw
if(sHeader!=null) BD hLz
{ k|^vCZ<(x
if(sHeader.equals("Content-Length")) ;JAK[o8i
{ J=@hk@Nq#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JR/W9i
break; 2y^Uk,g
} Er`TryN|}
} *]FgfttES
else O-i4_YdVt
break; F\;2i:(
} U%Dit
} h{\t*U54'
catch(IOException e){e.printStackTrace ();} d "2wO[
catch(Exception e){e.printStackTrace ();} et@">D%;]
,r@xPZPz:e
ex.+'m<g
Utility.log(nFileLength); -y%QRO(
I9;xzES
"Lb fF
return nFileLength; yU*u
} U> W|(Y
F@g17aa
4/b(Y4$,[r
//保存下载信息（文件指针位置） 2>g^4(
private void write_nPos() xne]Q(B>
{ miwf&b
try{ w_\nB}_
output = new DataOutputStream(new FileOutputStream(tmpFile)); gRHtgR)T3
output.writeInt(nStartPos.length); 5;}2[3}[
for(int i=0;i<nStartPos.length;i++) Bu&So|@TL
{ Umij!=GPG^
// output.writeLong(nPos); 1bd$XnU
output.writeLong(fileSplitterFetch.nStartPos); 2v4W6R
output.writeLong(fileSplitterFetch.nEndPos); wXz\NGW
} TFo}\B7
output.close(); 'gYg~=
} L"4]Tm>zq
catch(IOException e){e.printStackTrace ();} s}s|~
catch(Exception e){e.printStackTrace ();} Is ot4HLM
} ~H7!MC~K
vlvvi()
Z A[)
//读取保存的下载信息（文件指针位置） Cc2MYm8
private void read_nPos() kj-=xhJ{=
{ DjY8nePyE
try{ ,}KwP*:Z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5lGQ#r
int nCount = input.readInt(); p:Oz<P
nStartPos = new long[nCount]; a%v>eXc
nEndPos = new long[nCount]; v_.HGGS
for(int i=0;i<nStartPos.length;i++) e#1.T
{ ^}hJL7O'
nStartPos = input.readLong(); t-x[:i
nEndPos = input.readLong(); vG2.]?
} wE?CvL
input.close(); ~JLYhA^'+<
} @cPflb
catch(IOException e){e.printStackTrace ();} 7 I@";d8~
catch(Exception e){e.printStackTrace ();} x7HA722w
} 5\xr?`VZ
P8<hvMF
z{=v)F5y
private void processErrorCode(int nErrorCode) >otJF3zw
{ PYu$1o9+N
System.err.println("Error Code : " + nErrorCode); f}2;N
} 9)Ly}Kzx
?,>5[Ha^?
Dm^l?Z
//停止文件下载 GB=bG%Tb
public void siteStop() 2$tQ @r
{ Y[@0qc3UO
bStop = true; #jm@N7OZ
for(int i=0;i<nStartPos.length;i++) O5M2`6|As
fileSplitterFetch.splitterStop(); []gRfM]$&
>L=;"+B0U&
JCD?qeTg
} t3a#%'Dv
} x9&p!&*&IT
//负责部分文件的抓取 )b9_C O}
**FileSplitterFetch.java `c9'0*-
*/ <aXoB*Y
package NetFox; W~yLl%
Im+7<3Z
j`9Qzi1
import java.io.*; p?kvW42/
import java.net.*; `7\H41%\pp
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NH4?q!'G
public class FileSplitterFetch extends Thread { \7 Gz\=\LR
CdL.?^
,rai%T/rL
String sURL; //File URL |z*>ixK
long nStartPos; //File Snippet Start Position >Nh`rkR2[
long nEndPos; //File Snippet End Position g YUTt
int nThreadID; //Thread's ID iZ "y7s
boolean bDownOver = false; //Downing is over Zi*%*nX
boolean bStop = false; //Stop identical n}OU Y
FileAccessI fileAccessI = null; //File Access interface n}q$f|4!
({ k7#1 h8
? |VysJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException P,ydt
{ GW/WUzK
this.sURL = sURL; 'Wp@b678
this.nStartPos = nStart; ]]PE#DDg
this.nEndPos = nEnd; V{ |[oIp
nThreadID = id; > c:Zx!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RG}}Oh="v
} *|KVN&#
V;;#/$oU:4
d.AC%&W
public void run() #U"1 9@|}
{ J@Yj\9U
while(nStartPos < nEndPos && !bStop) J>h;_jA
{ s[X B#)H4
$r15gfne>
:)4*^a/lC
try{ H+x#gK2l
URL url = new URL(sURL); vQHpf>o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D/:3RZF
httpConnection.setRequestProperty("User-Agent","NetFox"); VB"(9O]
String sProperty = "bytes="+nStartPos+"-"; ="(>>C1-
httpConnection.setRequestProperty("RANGE",sProperty); x0<^<D&Q
Utility.log(sProperty); FN\GE\H
Hi8Y6|y$D
(a#pvEY
InputStream input = httpConnection.getInputStream(); |}Ph"g2D,
//logResponseHead(httpConnection); -N# #w=
7 :U8 f:
$[z<oN_Q
byte[] b = new byte[1024]; l1r_b68
int nRead; +t"j-}xzE
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >];"N{ A
{ IU9, (E
nStartPos += fileAccessI.write(b,0,nRead); (p,}'I#i*
//if(nThreadID == 1) <\aU"_D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,LUTHWEo"I
} wS$46M<
gtYRV*^q
28UVDG1?
Utility.log("Thread " + nThreadID + " is over!"); >r}Vf9 5[N
bDownOver = true; 9)lZyE}
//nPos = fileAccessI.write (b,0,nRead); 3U;1D2"AE
} D=&K&6rr
catch(Exception e){e.printStackTrace ();} GOVAb'
} n9] ~
} W[|[;{
c;!9\1sr
Ac\W\=QvB
//打印回应的头信息 hQ';{5IKvC
public void logResponseHead(HttpURLConnection con) a.,_4;'UE1
{ %rcFT_
for(int i=1;;i++) i!,HB|wQ
{ v8'5pLt"
String header=con.getHeaderFieldKey(i); (oYW]c}G,
if(header!=null) Xw^X&Pp
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UvBnf+,
Utility.log(header+" : "+con.getHeaderField(header)); o^GC=Aca`
else .'lN4x
break; Dl A Z"C
} 'C~9]Y].
} ipZHSA
%h/! Y<%
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public void splitterStop() t?3BCm$Mi
{ TQ'e
bStop = true; qjLo&2)
} o](.368+4
h=[-Er'B
?v.Gn9Z&
} ;BVDt
}cW#045es
eP= j.$
/* q"nGy#UWR
**FileAccess.java r/Dd&x
*//文件访问(定位，写) =P]GPEz_
package NetFox; fU ={a2
import java.io.*; 61:9(*4~!F
CQ>]jQ,2
,` o+ ?
public class FileAccessI implements Serializable{ 5i9Ub|!P
) ,Npv3(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #r}uin*jD
RandomAccessFile oSavedFile; %wW'!p-<
long nPos; 6~@5X}^<0
Z4@y?fv7s
EfKntrom[
public FileAccessI() throws IOException bQ.nFa']
{ >76 |:Nq
this("",0); 1b[NgOXY=
} s<VJ`Ur
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`M]BhW)
public FileAccessI(String sName,long nPos) throws IOException 5/(sjMB
{ D|TR!
oSavedFile = new RandomAccessFile(sName,"rw"); wY`#$)O0*
this.nPos = nPos; #Fzb8Yo
oSavedFile.seek(nPos); 6[+j'pW?
} (9'be\
6t$N78U
pVz*ZQ[]
public synchronized int write(byte[] b,int nStart,int nLen) `^e*T'UPl
{ \(bj(any
int n = -1; 3+zzi
try{ 5rN7':(H!%
oSavedFile.write(b,nStart,nLen); w%2ziwgh
n = nLen; AY;<q$8j%,
} @,Jb7V<
catch(IOException e) ;qb Dbg
{ T 9MzUV&
e.printStackTrace (); +f]u5p[
} 'M-)Os"
K0 QH?F
AysL-sqR
return n; CjV7q y
} kQ[Jo%YT?E
zzE]M}s
N'a?wBBR
} 3P`WPph
^XNw$@&',
y9ip[Xn-$:
/* X2{`l8%Ek
**SiteInfoBean.java xD^wTtT
*/ D}Au6
package NetFox; Iu%^*K%
W1`Dx(g
4znH$M>bU
public class SiteInfoBean { 0<3E
G g(NGT
9BO|1{
private String sSiteURL; //Site's URL Lz?*B$h
private String sFilePath; //Saved File's Path OOfyGvs
private String sFileName; //Saved File's Name z6 a,0&;-L
private int nSplitter; //Count of Splited Downloading File ~f .y:Sbb
nfa_8
yIWc\wv
public SiteInfoBean() ^8Z@^M&O"
{//nSplitter的缺省值为5 ~;!BDLMC6
//default value of nSplitter is 5 X'xUwT|_+
this("","","",5); )# p.`J
} |SxMN%M!
yYM_lobn
'H!V54 \j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !"`Jqs
{ HmW=t}!
sSiteURL= sURL; n 3h^VQ*]G
sFilePath = sPath; ^K"ZJ6?+1
sFileName = sName; ;*nh=w
this.nSplitter = nSpiltter; ]I8]mUiUH
1z3]PA!R
hRa\1Jt>a
} tg3zXJ4k_
*/4tJG1U
}'PG!+=I
public String getSSiteURL() K[e`t%2_
{ `t%|.=R
return sSiteURL; 40R"^*
} =,O/,2)
(X*'y*:
UmYD]
public void setSSiteURL(String value) xC'mPcU8
{ )y(oHRCp->
sSiteURL = value; -Sx0qi'%
} _a fciyso
PBCb0[\
zaH 5 Km_j
public String getSFilePath() $y8mK|3.3u
{ JR])xPI`
return sFilePath; PL9<*.U"=
} WUzSlZq
K!9y+%01
FMoJ"6Q
public void setSFilePath(String value) h>~jQ&\M
{ yq1Gqbh l
sFilePath = value; ,|6Y\L
} 1X[73
?Y%}(3y
%B[YtWqm`/
public String getSFileName() 0K&_D)
{ $I\))*a
return sFileName; 4A;[sm^f
} 4tbw*H5!5
;9}w|!/
+8]W\<Kp
public void setSFileName(String value) mp!YNI
{ a:=q8Qy
sFileName = value; XAw2X;F%
} kZJt~}
>Dk1axZ!>/
izXbp02
public int getNSplitter() th5 X?so
{ JtSuD>H`"
return nSplitter; @m5O{[euj<
} Lc58lV=
AqKHjCI
u wH)$Pl
public void setNSplitter(int nCount) J>><o:~@
{ !>CE(;E>z
nSplitter = nCount; FX{~"
} B0 6s6Q
} =AWX +znP
eL<m.06cfY
~D<7W4c
/* f+*J ue
**Utility.java P h9Hg'
*/ VI(RT-S6
package NetFox; 0eQ~#~j&
eKL]E!
O]c=Yyl
public class Utility { ='7er.~\
:Tlf4y:/w
s]$HkSH
public Utility() N7d17c. 5
{ 99\{!W
r~8D\_=s
%M|Z}2qv
} kqj;l\N
l[tY,Y:4qO
//线程睡眠 Ah6wU|_-g
public static void sleep(int nSecond) CnxK+1n l
{ b=6MFPbg
try{ LXBbz;vYl
Thread.sleep(nSecond); hB|H9+
} \hjk$Gq
catch(Exception e) \4[c}l
{ jlYD~)
e.printStackTrace (); 0!9?H1>
} k! J4Z${k
} lcu("^{3
_fczE~O/
//日志 y#hga5
public static void log(String sMsg) <C7M";54-
{ F Q8RK~?`
System.err.println(sMsg); 7Vz[ji
} i /O1vU#
zvek2\*rO
`_NnQ%
public static void log(int sMsg) jF%)Bhn(
{ tIz<+T_
System.err.println(sMsg); w.4u=e >Z4
} V_)5Af3wY
} RB S[*D
Jngll
-/(DPx
/* {0NsDi>(2
**TestMethod.java )GiFkG
*/ 6vD]@AF
package NetFox; SREDM
(SgEt
p9FA_(`^
public class TestMethod { R&u)=~O\5
e67c:Z
'Z*\1Ci
public TestMethod() nUI63?
{ ///xx/weblogic60b2_win.exe uR06&SaA>
try{ g|&.v2 '
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?D*Hl+iu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u4b3bH9U
SiteFileFetch fileFetch = new SiteFileFetch(bean); !SLP8|Cd
fileFetch.start(); jRv;D#Hp
} LVR;&Z>j
catch(Exception e){e.printStackTrace ();} Zd[y+$>
[?|l X$<
tJ?qcT?
} EmtDrx4!(f
bqw/O`*wfN
WrE-Zti
public static void main(String[] args) ]t.WJC %
{ :wv :#EaH
new TestMethod(); ^]#Ptoz^(l
} xh+AZ3
} Lu8%qcC
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