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)); m,]M_y\u
} _&m
for(int i=0;i<nEndPos.length-1;i++) -vC?bumR%
{ }' t*BaU
nEndPos = nStartPos[i+1]; Djf,#&j!3
} o,RLaS,BK'
nEndPos[nEndPos.length-1] = nFileLength; lq!l{[Xp
} yS-owtVCGF
} `_v|O{DC{
^UK6q2[
x_5H_! \#
//启动子线程 ];go?.*C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; XX(;,[(_
for(int i=0;i<nStartPos.length;i++) ?Yp: h
{ }mC-SC)oSi
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AHR[i%3W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `p%&c%*A
nStartPos,nEndPos,i); $Mp#tH28
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4m6E~_:F
fileSplitterFetch.start(); F 'U Gp
} @YTZnGG*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bXiT}5mJU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5q?ZuAAA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b=+'i
nEndPos = " + nFileLength); NUH#
// fileSplitterFetch[nPos.length-1].start(); /P0%4aWu=
H;$OCDRC
|ldRs'c{
//等待子线程结束 6(}8[i:
//int count = 0; Pw'3ya8
//是否结束while循环 m.p{+_@M&
boolean breakWhile = false; 8+1tys
7>J8\=
#\$R^u]!
while(!bStop) 5!G}*u.
{ OE/O:F:1j
write_nPos(); HLU'1As65
Utility.sleep(500); JQ8wL _C>
breakWhile = true; X}xy v
/%U+kW
a ^b_&}y
for(int i=0;i<nStartPos.length;i++) Bn/{J
{ GV([gs
if(!fileSplitterFetch.bDownOver) igsJa1F
{ X&6p_Lo
breakWhile = false; i1?H*:]
break; iVt6rX
} x,z+l-y
} NQ!jkojD
if(breakWhile) q8.K-"f(Q
break; MDS;qZx=
0>m-J
aQaO.K2
//count++; u%S&EuX
//if(count>4) yla&/K;|*
// siteStop(); F%x8y
} j']m*aM1>
`'5(4j
(AdQ6eGMb
System.err.println("文件下载结束！"); Q%(LMq4UG
} W^q;=D6uh
catch(Exception e){e.printStackTrace ();} |[?"$g9v
} ".eD&oX{
Z*QsDS
nJ4i[j8
//获得文件长度 Qsc%qt-l
public long getFileSize() /4]M*ls
{ QOkPliX
int nFileLength = -1; m-UI^M,@<
try{ [dL4u^]{
URL url = new URL(siteInfoBean.getSSiteURL()); :0j9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2*5Z| 3aX
httpConnection.setRequestProperty("User-Agent","NetFox"); ~w'M8(
t+5JIQY>
RJ1Q.o
int responseCode=httpConnection.getResponseCode(); V7!x-E/
if(responseCode>=400) Mjrl KI}f/
{ o@r+Y
processErrorCode(responseCode); eqQAst#~
return -2; //-2 represent access is error rm NqS+t
} pUWj,&t
2`Xy}9N/Y
z)r)w?A
String sHeader; bH&Cbme90-
w3c[t~R8
DJ;G0*
for(int i=1;;i++) TDdFuO'}
{ b}p0&%I
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }\B`tAN
//Utility.log(in.readLine()); hV/$6 8A_
sHeader=httpConnection.getHeaderFieldKey(i); 7^h?<X\
if(sHeader!=null) *Y6BPFE*4
{ "*WzoRA={
if(sHeader.equals("Content-Length")) =m=`|Bn
{ !12W(4S5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); H~1*`m
break; -#H>kbs
} ^S'}RZ*>
} ;GO>#yg4Eh
else s2Ivd*=mT
break; veg\A+:'
} !q! =VC
} RZ9vQ\X U)
catch(IOException e){e.printStackTrace ();} 7E4=\vM
catch(Exception e){e.printStackTrace ();} eZ y)>.6Z
;OQ{
|0ahvsrtW
Utility.log(nFileLength); l njaHol0
3HC aZ?Ry'
v&%GK5j7O
return nFileLength; ]FvN*@lG
} [nxjPx9-
SEF/D0
H?8KTl=e
//保存下载信息（文件指针位置） JNRG[j
private void write_nPos() DHJh.Y@H
{ iTi<X|X
try{ IM}T2\tZ}
output = new DataOutputStream(new FileOutputStream(tmpFile)); p mcy(<
output.writeInt(nStartPos.length); |_8-3
for(int i=0;i<nStartPos.length;i++) lqa.Nj
{ a-,!K
// output.writeLong(nPos); !-%i" a
output.writeLong(fileSplitterFetch.nStartPos); ZkkXITQkPM
output.writeLong(fileSplitterFetch.nEndPos); @kn0f`
} 5zX;/n~
output.close(); /i$E|[
} _`|Hk2O
catch(IOException e){e.printStackTrace ();} /pZLt)=P
catch(Exception e){e.printStackTrace ();} gX5I`mm
} dU\,>3tG
V6?ku6k
xWD=",0+
//读取保存的下载信息（文件指针位置） wj9CL1Gx
private void read_nPos() qm&}^S
{ Id(o6j^J_
try{ =xWZJ:UnU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /Ou`$2H87
int nCount = input.readInt(); 6]rIYc[,
nStartPos = new long[nCount]; k!b\qS~Q
nEndPos = new long[nCount]; Mb=vIk{Bf
for(int i=0;i<nStartPos.length;i++) (EGsw o
{ mnu4XE#|
nStartPos = input.readLong(); ge9j:S{
nEndPos = input.readLong(); 9%j_"+<c
} N&U=5c`Q'
input.close(); i)g=Lew
} 2@@OjeANsX
catch(IOException e){e.printStackTrace ();} LX'.up11X5
catch(Exception e){e.printStackTrace ();} \B8tGog
} z;@;jQ7
pI|Lt
uuHR!
private void processErrorCode(int nErrorCode) 3:7J@>
{ -z./6dQ
System.err.println("Error Code : " + nErrorCode); :TqvL'9o
} j{SRE1tqh
t/LQ|/xo
fGHYs
//停止文件下载 EFu2&P
public void siteStop() &WE|9
{ vF0#]
bStop = true; d76k1-m\o
for(int i=0;i<nStartPos.length;i++) l9"0Wu@_x
fileSplitterFetch.splitterStop(); 3~}G~ t
[URo#
hC?:XVt
} $As;Tvw.
} `@q[&^
//负责部分文件的抓取 u~7mH
**FileSplitterFetch.java l^w=b~|7=
*/ Nl,M9
package NetFox; xQ9P'ru
X:bv ?o>Y
~q4KQ&.!
import java.io.*; %bgjJ`
import java.net.*; orYE&
#'fh'$5"
t=o0 #jo
public class FileSplitterFetch extends Thread { l5QH8eNwME
x7)j?2
<|[G=GA\S!
String sURL; //File URL 5drc8_fZ
long nStartPos; //File Snippet Start Position @H2c77%
long nEndPos; //File Snippet End Position DW&%"$2
int nThreadID; //Thread's ID CRf!tsj@
boolean bDownOver = false; //Downing is over F]DRT6)
boolean bStop = false; //Stop identical W~(@*H
FileAccessI fileAccessI = null; //File Access interface "{1`~pDj?
8TGO6oY+=
VTQ V]>|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A5cx!h
{ . >[d:0
this.sURL = sURL; cih@:=Qy
this.nStartPos = nStart; |VxEWU/
this.nEndPos = nEnd; ["Mq
nThreadID = id; B,@geJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Dn~r~aR$g
} ivDmPHj{
8+Sa$R
'RK.w^
public void run() ~sj'GEhEg
{ `!WtKqr%B
while(nStartPos < nEndPos && !bStop) ?,uTH 4
{ _L 5<
yW5/Y02
s\i:;`l:=5
try{ r8>(ayJ,
URL url = new URL(sURL); BK`NPC$a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @v{lH&K:;
httpConnection.setRequestProperty("User-Agent","NetFox"); TP7'tb
String sProperty = "bytes="+nStartPos+"-"; IX@g].)C
httpConnection.setRequestProperty("RANGE",sProperty); "~-H]9
Utility.log(sProperty); 3SI:su
jej|B#?`
`2N&{(
InputStream input = httpConnection.getInputStream(); vM )2F
//logResponseHead(httpConnection); p|fSPSz
X,-QxV=lc)
ev~/Hf
byte[] b = new byte[1024]; C+ibLS4i
int nRead; aDEz|>q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >SRUC
{ Tk~RT<\Ab+
nStartPos += fileAccessI.write(b,0,nRead); Tj5G /H>
//if(nThreadID == 1) JHQc)@E}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =P'33) \ )
} vxuxfi8x
!Rp
4#hDt^N~
Utility.log("Thread " + nThreadID + " is over!"); _ nFsC
bDownOver = true; \i1>/`F
//nPos = fileAccessI.write (b,0,nRead); b^ wWg
} R-odc,P=
catch(Exception e){e.printStackTrace ();} L(Ww6oj
} O`Ht|@[6
} 70pt5O3]
eyq\a'tyB
YbCqZqk
//打印回应的头信息 >!u@>
public void logResponseHead(HttpURLConnection con) 1K(a=o[Ce
{ S}fU2Wi
for(int i=1;;i++) QY14N{]T\p
{ }{FKs!(4
String header=con.getHeaderFieldKey(i); P$l-p'U-
if(header!=null) yLv jfP1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "mT95x\NA\
Utility.log(header+" : "+con.getHeaderField(header)); "s[Y$!#
else ;/tZsE{
break; Qdepzo>E
} m ,B,dqT
} dzA5l:5
IX/FKSuq
$BIQ#T>qK
public void splitterStop() W?+U%bIZ9
{ ?t;>]Wo;
bStop = true; Xxl>,QUA
} F\pw0^K;N
>R|*FYam
/JP]5M)
} f1eY2UtWQ
gkxEy5c[
s=)0y$
/* do3 BI4Q
**FileAccess.java [h"#Gwb=;
*//文件访问(定位，写) ;=rMIi
package NetFox; [>`[1;aX
import java.io.*; mX@Un9k
*7`N^e
&uLxAw
public class FileAccessI implements Serializable{ 9`[#4'1Mik
,p(4OZz5,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 sU7>q}!
RandomAccessFile oSavedFile; >;E[XG^
long nPos; qg7] YT&
79.J`}#
5f54E|vD
public FileAccessI() throws IOException 8mjP2
{ iU)-YFO
this("",0); D+ki2UVt&
} NW-l_]k
7Pt*V@DHS
$D,m o2I
public FileAccessI(String sName,long nPos) throws IOException doR'E=Z4h
{ +{%@kX<V_
oSavedFile = new RandomAccessFile(sName,"rw"); +n1jP<[<N
this.nPos = nPos; ^iaeY jI
oSavedFile.seek(nPos); vBUl6EmWu
} OtopA)
?nm:e.S+?
!U02>X
public synchronized int write(byte[] b,int nStart,int nLen) KR
{ X^3 0a*sj
int n = -1; )g4oUZDF
try{ ^$][ah
oSavedFile.write(b,nStart,nLen); q.(p.uD
n = nLen; niO(>
} T;-Zl[H
catch(IOException e) ~"l a2
{ vPG!S{4
e.printStackTrace (); b0a'Y"oef4
} >K`.!!av,Y
M mg#Vy~
oz}p]l7
return n; uo1G
} Z2chv,SqCJ
uCK!lq-
=goZI67
} 2|k*rv}l
h.)2,
:oB4\/(G#
/* V07x+ovq
**SiteInfoBean.java <_*8a(j3
*/ ;WIL?[;w
package NetFox; 0w >DU^+
$,k SR}
Q^Ln`zMe
public class SiteInfoBean { ?`F")y
6'C!Au
";~}"Yz?[
private String sSiteURL; //Site's URL ]\nG1+ta
private String sFilePath; //Saved File's Path K{VF_S:
private String sFileName; //Saved File's Name BfOG e!Si
private int nSplitter; //Count of Splited Downloading File =erA.u
#SY8Zv
X7kJWX
public SiteInfoBean() ;>=hQC{f>
{//nSplitter的缺省值为5 |Sg *j-.
//default value of nSplitter is 5 TGLkwXOkT
this("","","",5); oWyg/{M
} [BhpfZNKRA
S&-sl
sF;1)7]Pq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +N[dYm
{ bcpH|}[F)
sSiteURL= sURL; ?xf59mY7
sFilePath = sPath; | -Di/.
sFileName = sName; /2u;w!oi.
this.nSplitter = nSpiltter; :Puv8[1i
mxHNK4/
_}]o~
} 4\(;}M-R{
Y,D\_il_
,Ucb)8a
public String getSSiteURL() HZQI|
{ }jd[>zk
return sSiteURL; eEsEW<su
} 9szE^kHS9
)I+1 b !U
nGW wXySq
public void setSSiteURL(String value) if5Y!Tx?G
{ 5*buRYck0
sSiteURL = value; oW]&]*>J
} =Ak>2
v85&s
:&)RK~1m_
public String getSFilePath() B^Ql[m&5+
{ 62EJ# q[
return sFilePath; [ur/`
} mC~W/KReA
B4R,[WE"
`@.YyPxX\
public void setSFilePath(String value) svpWABO
{ ! # tRl
sFilePath = value; ECkfFE`
} |0f\>X I
qw87B!D
O8u"Y0$*w
public String getSFileName() 2|}p&~G(
{ 8Z3+S)6
return sFileName; &s/aJgJhp
} ?5mVC]W?]
^Hq}9OyS9
kq%`9,XE
public void setSFileName(String value) 6}NvVolr
{ GWE`'V
sFileName = value; uy\YJ.WMQ
} [9?=&O#*
{OAy@6 +
}Tc)M_
public int getNSplitter() PLLlo~Bb
{ 66L*6O4
return nSplitter; [RpFC4W
} p'w[5'
[F/xU
9:~,TH
public void setNSplitter(int nCount) $E7yJ|p{
{ N_0&3PUSM
nSplitter = nCount; McsqMI6
} * n!0
} ^|sxbP
q=nMZVVlF(
7DYD+N+T
/* h y[_
**Utility.java DBmcvC
*/ *R~oA`
package NetFox; *fd` .}
!d(!1fC
5h{Hf]A
public class Utility { LnJ7i"Q
+H<%)Lk J
8=nm`7(]
public Utility() }p- %~Y
{ 5Rec}H
]lO$oO
A`N;vq,
} ;,4J:zvZdQ
|u}sX5/q
//线程睡眠 H>7!+&M
public static void sleep(int nSecond) SiBbz4
{ e@,L~\
try{ Fk9(FOFg
Thread.sleep(nSecond); Mvcl9
} F 1zc4l6
catch(Exception e) 9MYt4
{ 3p4bOT5
e.printStackTrace (); b5)>h
} `GDYL7pM(
} PRah?|*0s
33;|52$
//日志 ;q^YDZ'
public static void log(String sMsg) kXjpCtCu
{ G/ ^|oJ/G
System.err.println(sMsg); l|up3A3)
} L+kS8D<
a0LX<}
"Q J-IRt&
public static void log(int sMsg) '+QgZ>q"
{ #xo&#FIH
System.err.println(sMsg); (@#Lk"B
} mn4;$1~e>H
} ut,"[+J
L%8"d6
plIx""a^h
/* 'K"*4B^3
**TestMethod.java p-6.:y
*/ iLI]aZ
package NetFox; nm~
J~Ph)|AiS
H5%I?ZXw4
public class TestMethod { Qv=Z
_k@l-Bj
#FQVhgc
public TestMethod() 52 A=c1kb
{ ///xx/weblogic60b2_win.exe [}Iq-sz;0
try{ YOoP]0'L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 68>zO%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?d0Dfqh_
SiteFileFetch fileFetch = new SiteFileFetch(bean); >k jJq]A2
fileFetch.start(); >k#aB.6
} f:0n-me
catch(Exception e){e.printStackTrace ();} n%0vQ;Z1
_t[%@G>P
!Yf0y;e|:
} l85"C
0cbF.Um8
J|q_&MX/
public static void main(String[] args) mNYz7N
{ _L72Ae(_
new TestMethod(); wz#n$W3mGf
} e+WVN5"ID>
} )5v .9N6v
点击下载更多相关资料