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)); Hkj| e6
} O`(it%Ho!
for(int i=0;i<nEndPos.length-1;i++) f]^ @z<FC
{ $Jj0%?;
nEndPos = nStartPos[i+1]; Tb]' b
} SB!m&;Tb
nEndPos[nEndPos.length-1] = nFileLength; C)s*1@af
} :20k6)
} v{>9&o.J
v]KI=!Gs
y/A<eHLy
//启动子线程 @Cd}1OT)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }A_>J7w
for(int i=0;i<nStartPos.length;i++) ~f%AbDye
{ t!vlZNc
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o)6udRzBv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8"S? Toqq
nStartPos,nEndPos,i); \U'TL_Ql
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5'O.l$)y
fileSplitterFetch.start(); 7llEB*dSA
} iJK rNRj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4K*DEVS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]z/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s((_^yf
nEndPos = " + nFileLength); ?GGh )";y
// fileSplitterFetch[nPos.length-1].start(); @-qC".CI
()i!Uo
QJ-?67_i
//等待子线程结束 EC|b7
//int count = 0; Z})n%l8J]p
//是否结束while循环 5B=Wnau
boolean breakWhile = false; 6MRS0{
./;*LD
-Qco4>Z8
while(!bStop) -?<L"u
{ 5Bc)QKh`l|
write_nPos(); ? &;d)TQ
Utility.sleep(500); /%GMbO_
breakWhile = true; OL"So u4
KbV%8nx!!
zoBjrAyD
for(int i=0;i<nStartPos.length;i++) y7s.6i}7
{ Y:="vWWG
if(!fileSplitterFetch.bDownOver) cM'5m
{ =8fZG t
breakWhile = false; dQL! >6a
break; OG}D;Ew
} ;w}5:3+
} w]0jq U6
if(breakWhile) DWH)<\?
break; Uyyw'Ni
Kq0hT4w
J#W>%2"s
//count++; &hYjQ&n
//if(count>4) jNNl5.
// siteStop(); t|zLR
} @V-CG!
&_E*]Sj\
W\<5'9LNb
System.err.println("文件下载结束！"); HCifO
} ,Pd2ZfZ
catch(Exception e){e.printStackTrace ();} 0-+`{j
} Vkb&' rXw+
pf`li]j'V
2={ g'k(
//获得文件长度 uQ.VW/>
public long getFileSize() BPd]L=,/
{ MY[" zv
int nFileLength = -1; 8)k.lPoo.
try{ w,.Hdd6
URL url = new URL(siteInfoBean.getSSiteURL()); , 0rC_)&B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :+,qvu!M7
httpConnection.setRequestProperty("User-Agent","NetFox"); %tzz3Y
K`2a{`
?Xo9,4V1
int responseCode=httpConnection.getResponseCode(); vu.f B4
if(responseCode>=400) Ic/<jFZXM
{ !<2*B^
processErrorCode(responseCode); ':w6{b
return -2; //-2 represent access is error 2h6F j&
} zj;y`ENj
F<w/@.&m
;SVF"Uo
String sHeader; i9M6%R1m}E
Ve8`5
[P{Xg:0
for(int i=1;;i++) z[ ;{p.W
{ . yu
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); LVLh&9
//Utility.log(in.readLine()); UrxgKTry
sHeader=httpConnection.getHeaderFieldKey(i); &/, BFx"
if(sHeader!=null) cY>;(x@
{ Ec6{?\
if(sHeader.equals("Content-Length")) %3VwCuE
{ }%R6Su]y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xt"/e-h}
break; ]@ [=FK^
} }wkBa]
} <ZrZSt+<
else W^+bgg<.
break; =8dCk\/
} R4JO)<'K&
} l>&)_:\
catch(IOException e){e.printStackTrace ();} {YbqB6zaM
catch(Exception e){e.printStackTrace ();} M3F8@|2
a<gzI
(lPNMS|V
Utility.log(nFileLength); 9au)K!hN
s_Dl8O4u
WuGm~<NS
return nFileLength; #G{T(0<F
} 6U+#ADo
>uJrq""+
c*1x*'j.
//保存下载信息（文件指针位置） ?I/,r2ODLh
private void write_nPos() SKfv.9
{ iKS9Xss8
try{ 6OTxtk
output = new DataOutputStream(new FileOutputStream(tmpFile)); #lLL5ji
output.writeInt(nStartPos.length); Da@tpKU)p
for(int i=0;i<nStartPos.length;i++) LL6f40hC
{ esu6iU@
// output.writeLong(nPos); WD?V1:>+
output.writeLong(fileSplitterFetch.nStartPos); 7\/O"Ot
output.writeLong(fileSplitterFetch.nEndPos); yMSRUQ x
} dF.T6b
output.close(); zPkg3H
} !s)$_tG
catch(IOException e){e.printStackTrace ();} 329xo03-[
catch(Exception e){e.printStackTrace ();} Yu1xJgl
} :6M0`V;L
Y]gt86
*,n7&
//读取保存的下载信息（文件指针位置） cq9Q7<&MF
private void read_nPos() ^3yjE/Wi"
{ wA~Nfn ^
try{ w\2[dd
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r2H'r ,N
int nCount = input.readInt(); rP\7C+
nStartPos = new long[nCount]; <0LB]zDWe6
nEndPos = new long[nCount]; wFd*6%
for(int i=0;i<nStartPos.length;i++) 4rzioIk
{ 462ae` 6l
nStartPos = input.readLong(); *r%mqAx(
nEndPos = input.readLong(); <m6I)}K
} p$%h!.~99T
input.close(); }.gg!V'9w
} u('OHPqq
catch(IOException e){e.printStackTrace ();} 0'~b<>G%
catch(Exception e){e.printStackTrace ();} bA^a@ lv a
} z vYDE]
n `Xz<Q!
Ti/iD2g
private void processErrorCode(int nErrorCode) (7wR*vO^
{ |(H|2]b4=
System.err.println("Error Code : " + nErrorCode); q-3KF
} <|`@K|N
RYhdf
BxT~1SBFq
//停止文件下载 N7jRdT2k%
public void siteStop() CM#EA"9
{ 88*RlxU
bStop = true; d!LV@</
for(int i=0;i<nStartPos.length;i++) <V8i>LBlz
fileSplitterFetch.splitterStop(); &sNID4FR
aw4+1.xy
T8(wzs
} ^+wzm2i
} t/D Q<B_
//负责部分文件的抓取 1*jL2P]D
**FileSplitterFetch.java :hr@>Y~r
*/ 7cy~qg
package NetFox; xXYens}
AP7W)S
R`?^%1^N
import java.io.*; 6;b 'j\jG
import java.net.*; Uy1xNb/d
C/vLEpP{(/
jlP7'xt1%
public class FileSplitterFetch extends Thread { ,qHG1#^
).S<{zm7
9]w0zUOL6
String sURL; //File URL ^U?(g0<"
long nStartPos; //File Snippet Start Position 9M=K@a
long nEndPos; //File Snippet End Position c\'pA^m6
int nThreadID; //Thread's ID ri;M7rg`.{
boolean bDownOver = false; //Downing is over Zs{R O
boolean bStop = false; //Stop identical Tz-cN
FileAccessI fileAccessI = null; //File Access interface iQIw]*h^
B<&_lG0sS
,+BgY4OY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException / IS WC
{ oQXkMKZ
this.sURL = sURL; wE \c?*k
this.nStartPos = nStart; eC{Z
this.nEndPos = nEnd; JT9<kB/07
nThreadID = id; KEN-G
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -]A#G`'
} .%<&W1
#G=QL(f>/
|*NrS<"
public void run() %Eh%mMb^
{ u_"h/)C'H
while(nStartPos < nEndPos && !bStop) -YyH"f
{ 4w6K|v<X
Y fA\#N0;3
X&~Eo
try{ R"o,m
URL url = new URL(sURL); NXNon*"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b . j^US^
httpConnection.setRequestProperty("User-Agent","NetFox"); HXHPz4
String sProperty = "bytes="+nStartPos+"-"; =k7\g /
httpConnection.setRequestProperty("RANGE",sProperty); $?-o
Utility.log(sProperty); zn!
49$4
K@~#Gdnl
InputStream input = httpConnection.getInputStream(); }x1IFTa!
//logResponseHead(httpConnection); /xbZC{R
IyN9 +
Y]K]]Ehp
byte[] b = new byte[1024]; CEq]B:[IC
int nRead; 0Ida]H
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) d@4!^vD;
{ #jx?uS
nStartPos += fileAccessI.write(b,0,nRead); -b}S3<15@
//if(nThreadID == 1) X4G55]D$>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 05 Q8`
} y;Ln ao7i
?|J+dW
~&3"Mi&>`
Utility.log("Thread " + nThreadID + " is over!"); 8#u_+;,p
bDownOver = true; U3K<@r
//nPos = fileAccessI.write (b,0,nRead); h}>/Z3*
} =hOa 0X=
catch(Exception e){e.printStackTrace ();} ] *VF Ws
} 3a}`xCO5
} mZVOf~9E
51ebE`
U(=9&c@]
//打印回应的头信息 PjW+V`
public void logResponseHead(HttpURLConnection con) c\{}FGC
{ C'2 =0oou
for(int i=1;;i++) Pq>[q?>?
{ I 47GQho
String header=con.getHeaderFieldKey(i); g Pj0H&,.
if(header!=null) hr6e1Er
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (zDk68=v
Utility.log(header+" : "+con.getHeaderField(header)); Su$1 t
else [(F<|f:n
break; dd7nO :]
} F'$S!K58
} $jh>zf
)9*3^v
EJ ~kZ3
public void splitterStop() Q9xx/tUW
{ )$h9Y
bStop = true; XJ~l5}y ]
} 3t{leuO'
lO:{tV
&N_c-@2O
} K!c@aD:#
eu]iwOc&p
' VEr4&
/* kz;_f
**FileAccess.java `N.$LY;8
*//文件访问(定位，写) eoe^t:5&
package NetFox; Qr%Jm{_o
import java.io.*; >[fVl8G_0
UdW(\%
y*b.eO
public class FileAccessI implements Serializable{ dX@A%6#?
q[OTaSQ~u^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .7gE^
RandomAccessFile oSavedFile; Qb't*2c%
long nPos; r82o[+$u0K
o$`kpr
UnWGMo?JEi
public FileAccessI() throws IOException J1p75c%
{ +aw>p_\
this("",0); 5J+V:Xu{
} ?5v5:U(A
{I-a;XBX
k gu[!hD1
public FileAccessI(String sName,long nPos) throws IOException nlebFDb7
{ (5q%0|RzRs
oSavedFile = new RandomAccessFile(sName,"rw"); RYZE*lWUh
this.nPos = nPos; ](=wlq)
oSavedFile.seek(nPos); qm}>J^hnB#
} s>VEuLY*
Sj{ia2AE_
rt^45~
public synchronized int write(byte[] b,int nStart,int nLen) {rvbo1t
{ t0J5v;
int n = -1; LJ(n?/z%
try{ /uE^H%9h
oSavedFile.write(b,nStart,nLen); [)SR$/A
n = nLen; ^[,s_34V
} ~x4B/zW?
catch(IOException e) oCKM5AVWsv
{ fQ36Hd?(5
e.printStackTrace (); <@e+-$
} |[37:m
p + l_MB
C. Ja;RFq
return n; O GFE*
} ~`\9Q
xe6_RO%
%+xwk=%*
} zzfn0g
80$0zbw$
&6t3SZV
/* a}Fkx
**SiteInfoBean.java Sc'c$/
*/ pH\^1xj =
package NetFox; zd9]qo
inBPT~y
&=-e`=qJ'6
public class SiteInfoBean { ]`@]<6
*F szGn<
r6n5Jz
private String sSiteURL; //Site's URL "@{4.v^}!
private String sFilePath; //Saved File's Path /:y2Up-
private String sFileName; //Saved File's Name pYfV~Q^3
private int nSplitter; //Count of Splited Downloading File IypWVr
Vj=Xcn#*8
3@yTzaq6
public SiteInfoBean() W ~Jzqp9g
{//nSplitter的缺省值为5 i$bzdc#s
//default value of nSplitter is 5 ]<q}WjXD'
this("","","",5); G*(K UG>
} *t.q m5h
whY~=lizn
|}M0,AS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) SH vaV[C
{ ;vJ\]T ml
sSiteURL= sURL; _V& !4Zd9:
sFilePath = sPath; {Vxc6,=
sFileName = sName; &"[)s[m+t
this.nSplitter = nSpiltter; Ak6MPuBB-
+mc[S
?Q96,T-) c
} PEW4J{(W
>I4p9y(u
^XBzZ!h|
public String getSSiteURL() 4bi NGl~
{ zj>aaY
return sSiteURL; q]eFd6
} [0&'cu>
F!gNt<fZ
Dn_"B0$lk
public void setSSiteURL(String value) 2~!R*i
{ dI^IK
sSiteURL = value; 6 u-$
} /mn-+u`K
SOp=~z
}!%JYG^!D
public String getSFilePath() 2mqK3-c
{ #ya\Jdx
return sFilePath; DH:GI1Yu>I
} GIm " )}W
1~2R^#rm
jg [H}
public void setSFilePath(String value) }bf=Ntk
{ 22`oFXb'
sFilePath = value; bmOqeUgB
} 5@`F.F>"
y=AsgJ
%MJL5
public String getSFileName() <4bz/^
{ =)I"wR"v$
return sFileName; E6Q]A~
} A8pj~I/*-
:dP~.ZY7
SY-ez91
public void setSFileName(String value) l{Jt sI
{ $Y6I_U
sFileName = value; 8Q2]*%
} T><{ze
5@P%iBA4(3
jn-QKdqM
public int getNSplitter() d^F|lc ]8
{ J["H[T*
return nSplitter; 0"EoC
} .yZm^&
QsiJ%O Q
Q}kfM^i
public void setNSplitter(int nCount) ~U6"?
{ VeZey)Q
nSplitter = nCount; OAv>g pw
} iF!mV5#
} Sd},_Kh
/X4yB"J>
zfhTc=(/
/* .K IVf8)"
**Utility.java N.Dhu~V
*/ *E:x E/M!2
package NetFox; qmZ2d!)o
o+nG3kRD
xXX/]x>
public class Utility { ><;Q@u5~
kt^yj"C>
NYBe"/}GS
public Utility() KOjluP
{ R A:jzht
![ZmV
57~Uqt
} nV}8M
(}Sr08m
//线程睡眠 >$\Bu]{1
public static void sleep(int nSecond) Sp:l;SGd
{ WsR+Np@c
try{ 4qhWm"&CM
Thread.sleep(nSecond); 5[C~wvO
} $>*Yhz `
catch(Exception e) rH&G<o&,
{ aD9rp V
e.printStackTrace (); 79ckLd9
} Sk:2+inU
} $;2)s}ci
Cq>6rn
//日志 P z ?m>>#
public static void log(String sMsg) 38~PWKt
{ %}q.cV
System.err.println(sMsg); @6 /yu>%
} jd 1jG2=f
G"T\=cQz
uWjN2#&,
public static void log(int sMsg) fc@'9-pt
{ $X\va?(
System.err.println(sMsg); ;+ azeW^
} 0VN7/=n|
} ,_jC$
@x1%)1
!Xj#@e
/* qI%&ay"/
**TestMethod.java G2`${aMS
*/ hQRL,?
package NetFox; vE%s,E,
~6`iY@)
*5k+t
public class TestMethod { wv?RO*E
BcQEG *N
E{4 e<%Y,
public TestMethod() gbDX7r-
{ ///xx/weblogic60b2_win.exe m:uPEpcU
try{ +dk fcG
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9sSN<7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f'X9HU{Cz
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~`qEWvPn
fileFetch.start(); mT@nn,
} n[,XU|2
catch(Exception e){e.printStackTrace ();} e_.Gw"/Yl
:^i^0dC
p[9s<lEh
} |mhKIis U
eQUe >*
+5!&E7bcd
public static void main(String[] args) `!vUsM.d
{ |4;UyHh
new TestMethod(); u.,Q4u|!
} .@#A|fgv
} 6cz/n8Mg
点击下载更多相关资料