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)); 4!I;U>b b
} wG,"ZN
for(int i=0;i<nEndPos.length-1;i++) S~Z`?qHWh
{ pE^jUxk6
nEndPos = nStartPos[i+1]; tH}$j
} _:ORu Vk
nEndPos[nEndPos.length-1] = nFileLength; !,I530eh7
} aDae0$lc.S
} P ]prrKZe,
GWQ_X9+q
zRz7*o&l
//启动子线程 #?V7kds]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `H^?jX>7
for(int i=0;i<nStartPos.length;i++) hv6w=?7
{ 8.g(&F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +FYQ7UE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +1R qo
nStartPos,nEndPos,i); ;)SWUXa;{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LK?V`J5wY
fileSplitterFetch.start(); x'uxSeH$
} M.[A%_|P
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r N.<S[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?)60JWOJ1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #wvmVB.5~
nEndPos = " + nFileLength); :'t+*{ff
// fileSplitterFetch[nPos.length-1].start(); W{{{c2.
nJ ZQRRa:C
?eU=xO
//等待子线程结束 =$^<@-;
//int count = 0; LHS^[}x^1
//是否结束while循环 #Is/j =
boolean breakWhile = false; bM9:h
uPp9 UW
+pq/:h
while(!bStop) IhRYV`:
{ -%h0`hOG{
write_nPos(); [xrM){ItW
Utility.sleep(500); 1\~-No
breakWhile = true; L, k\`9bQ
gLH#UwfJ
qXb{A*J
for(int i=0;i<nStartPos.length;i++) HoFFce7o
{ 8%Wg;:DZx
if(!fileSplitterFetch.bDownOver) ;`TSu5/
{ 3 E~d
breakWhile = false; 3XOf-v:~
break; L'*P;z7<
} l$:.bwXXO
} H=f'nm]dQ
if(breakWhile) 5z$>M3
break; M< T[%)v
rLy<3
8:iu 8c$
//count++; N@z+h
//if(count>4) EJbFo682
// siteStop(); @ZD/y%e
} 6*cY[R|q!
CXzN4!
?]d[K>bv
System.err.println("文件下载结束！"); @t;WdbxB%
} P/'9k0zs)
catch(Exception e){e.printStackTrace ();} -d|VXD5N
} "n4' \ig
S!/N lSr<
&)8-iO
//获得文件长度 Q]?Lg
public long getFileSize() v7L}I[f
{ 5_d=~whO&2
int nFileLength = -1; [CfA\-gx<f
try{ =>PBdW
URL url = new URL(siteInfoBean.getSSiteURL()); * MJl(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @k~_ w#
httpConnection.setRequestProperty("User-Agent","NetFox"); frYPC Irj
6]#\|lds1
|H,g}XWMU
int responseCode=httpConnection.getResponseCode(); rRfPq
if(responseCode>=400) A(xCW+h@)
{ /pa8>_,~
processErrorCode(responseCode); 8@S5P$b};
return -2; //-2 represent access is error %o~w
} 2WA =U]
D-/aS5wM
Mohy;#8Wk
String sHeader; Cw=wU/)
dXe. 5XC
qlUw;{;p
for(int i=1;;i++) 7jb{E+DrG
{ BBub'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Qe~2'Hw#9
//Utility.log(in.readLine()); L?@TF;
sHeader=httpConnection.getHeaderFieldKey(i); V!'N:je
if(sHeader!=null) s1[_Pk;!
{ bEXm@-ou
if(sHeader.equals("Content-Length")) +UK".
{ )A`Zgg'L7D
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K{ s=k/h
break; yxECK&&P0#
} G]Jchg <
} 8\M%\]_
else ~)S Q{eK?&
break; pearf2F
} H3#xBn>9
} >};6>)0
catch(IOException e){e.printStackTrace ();} yqg&dq
catch(Exception e){e.printStackTrace ();} No\H QQ
[N|/d#
I82?sQ7
Utility.log(nFileLength); !eoN
F4m Q#YlrS
8tc9H}>
return nFileLength; FmALmS
} ,|: a7b]
brQkVt_)EE
cI)XXb4
//保存下载信息（文件指针位置） W~1/vJ.*l
private void write_nPos() ;|2h&8yX(/
{ &h7q=-XU
try{ ;w(]z
output = new DataOutputStream(new FileOutputStream(tmpFile)); @-z#vJ5Qe{
output.writeInt(nStartPos.length); 2p(M`@
for(int i=0;i<nStartPos.length;i++) 5G~;g
{ ASuxty
// output.writeLong(nPos); )e)@_0
output.writeLong(fileSplitterFetch.nStartPos); K8dlECy
output.writeLong(fileSplitterFetch.nEndPos); ]Q\Ogfjp
} n'/w(o$&
output.close(); :!a9|Fh~
} lN,8(n?g
catch(IOException e){e.printStackTrace ();} E"Z9 NDgl#
catch(Exception e){e.printStackTrace ();} 8gap _qTo
} %6`{KT?
nL}bCX{
k'N `5M)
//读取保存的下载信息（文件指针位置） .+G),P)
private void read_nPos() #vy:aq<bjE
{ (/&IBd-
try{ JM{S49Lx
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %h**L'~``
int nCount = input.readInt(); H|='|k5Y.
nStartPos = new long[nCount]; 28[dTsd%
nEndPos = new long[nCount]; F|*{Ma
for(int i=0;i<nStartPos.length;i++) d{.cIv
{ Q6y883>9
nStartPos = input.readLong(); {~yj]+Im
nEndPos = input.readLong(); PUB|XgQDY:
} =*.Nt*;;
input.close(); %$j)?e
} EXDtVa Ot
catch(IOException e){e.printStackTrace ();} j%iz>
catch(Exception e){e.printStackTrace ();} D4yJ:ATO&
} 7N^9D H{`
0s = h*"[
iTU8WWY<
private void processErrorCode(int nErrorCode) Xj^6ZJc
{ %S8e:kc6
System.err.println("Error Code : " + nErrorCode); UA[2R1}d
} #q~SfG
1<]g7W
N2_j[Pe
//停止文件下载 (NUk{MTX
public void siteStop() >n@?F[Y
{ oK h#th
bStop = true; ;T2)nSAqt
for(int i=0;i<nStartPos.length;i++) pb`F_->uq
fileSplitterFetch.splitterStop(); 4Vj|k\vE4
Lj"~6l`)
xm>RLx}9
} DCb\=E
} ze Qgg|;
//负责部分文件的抓取 c,KT1me
**FileSplitterFetch.java YzU(U_g$
*/ L0SeG:
package NetFox; &I.UEF2,
mt7}1s,i[
/%Bc*k=ox
import java.io.*; 0SV#M6`GX
import java.net.*; t=iSMe
9+.0ZP?
B^Q\l!r
public class FileSplitterFetch extends Thread { zIWw055W
krZ J"`
v'B++-%
String sURL; //File URL o)KF+[^
long nStartPos; //File Snippet Start Position DO(-)izC
long nEndPos; //File Snippet End Position CzxU @
int nThreadID; //Thread's ID 1TfK"\
boolean bDownOver = false; //Downing is over hS&,Gm`^
boolean bStop = false; //Stop identical L)VEA8}
FileAccessI fileAccessI = null; //File Access interface )((Jnm D
2%N$Y]
nBL7LocvR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~C< X~$y&
{ ;]?1i4p)
this.sURL = sURL; W-%oj.BMA
this.nStartPos = nStart; ^~0Mw;n&
this.nEndPos = nEnd; CU 2;m\Hc
nThreadID = id; %'j)~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 s z/7cLo
} zF%CFqQ
x^}kG[s
i]*Wt8~!
public void run() (7x5
{ ,v:m
while(nStartPos < nEndPos && !bStop) ,FX;-nP%
{ DF'-dh</*
m8H|cQ@Uu
S pDVD
try{ V'~]b~R
URL url = new URL(sURL); Z{`;Ys:zk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bp2l%A;
httpConnection.setRequestProperty("User-Agent","NetFox"); R-J\c+C>W
String sProperty = "bytes="+nStartPos+"-"; Nh~ Hh(
httpConnection.setRequestProperty("RANGE",sProperty); "<0BCJJ
Utility.log(sProperty); -;'8#"{`^
QJp _>K
6} !n0
InputStream input = httpConnection.getInputStream(); aT[Z#Zd, N
//logResponseHead(httpConnection); }pj>BK>
?"PUw3V3lB
8 s!0Z1Roc
byte[] b = new byte[1024]; ]y@8mb&
int nRead; K8doYN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [o<R#f`
{ a ^<W ?Z
nStartPos += fileAccessI.write(b,0,nRead); =:[Jz1M5
//if(nThreadID == 1) WV!qG6\W
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Rj9z'?a9
} )I{41/_YA
4x.'H18
vmL%%7
Utility.log("Thread " + nThreadID + " is over!"); "T@9]>6.f
bDownOver = true; S*],18z?
//nPos = fileAccessI.write (b,0,nRead); qyv9]Q1
} %d*k3f }
catch(Exception e){e.printStackTrace ();} 314PcSc
} ^ruS
} oAe]/j$
}N(-e$88
E"bYl3
//打印回应的头信息 WM NcPHcj
public void logResponseHead(HttpURLConnection con) :y%%Vx~
{ (;P)oB"`C
for(int i=1;;i++) 0G1?
{ 6#fl1GdH-
String header=con.getHeaderFieldKey(i); \%=\_"^?
if(header!=null) ln)_Jf1r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8s pGDg\g
Utility.log(header+" : "+con.getHeaderField(header)); CL|t!+wU/
else _KC)f'Cx
break; Oga0CR_
} }9t$Cs%
} IBb3A
(%"M% Qko
P0S;aE
public void splitterStop() UvRa7[<y%%
{ (Mhj-0xf$
bStop = true; Ev%4}GwO4
} ;$l!mv7
L=3^A'|
Q^/66"Z:Z
} AZt~ \qf
/4+M0Pl
<splLZW3k
/* JLm0[1Lzd
**FileAccess.java OEy'8O$
*//文件访问(定位，写) lBh|+KN
package NetFox; vC[)/w
import java.io.*; #sdW3m_%
FiJJe
^RrufwUA
public class FileAccessI implements Serializable{ gBUtv|(@>[
o!^':mll
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Lgpj<H[
RandomAccessFile oSavedFile; G*uy@s:
long nPos; e*jt(p[Ge
NmYSk6kWJ
rc1EJ(c
public FileAccessI() throws IOException dQ@e+u5
{ Dg%zNi2GS
this("",0); 1uz9zhG><
} Kc_QxON4
YOwo\'|=
(o)nN8
public FileAccessI(String sName,long nPos) throws IOException .]0B=w* Z
{ /ZHuT=j1
oSavedFile = new RandomAccessFile(sName,"rw"); l;}D| 6+_W
this.nPos = nPos; )VQ:L:1t(
oSavedFile.seek(nPos); dbSIC[q
} I \zM\^S>]
7g}4gX's
FYR%>Em
public synchronized int write(byte[] b,int nStart,int nLen) ~{iBm"4
{ EMzJJe{Cv
int n = -1; p8hF`D~
try{ %YG ~ql
oSavedFile.write(b,nStart,nLen); GJai!$v
n = nLen; PF*<_p"j
} JVf8KHDj
catch(IOException e) `DIIJ<;g
{ 4_3Jpz*
e.printStackTrace (); v>YdPQky
} 5 :6^533]
H`CDfTy
"pdmz+k8S
return n; I0P)DR
} bPEf2Z G4
;X-~C.7k
FFb`4.
} Enm#\(j
;0O3b
8hba3L_Z
/* .pNWpWL.
**SiteInfoBean.java )dgXS//Y
*/ A-1Wn^,>*
package NetFox; F2]v]]F!
K#H}=Y A
:&}(?=<R}L
public class SiteInfoBean { 7SLJLn3d
Ac'[(
f305yo
private String sSiteURL; //Site's URL I]bqle0M
private String sFilePath; //Saved File's Path evNo(U\C
private String sFileName; //Saved File's Name I!&|L0Qq
private int nSplitter; //Count of Splited Downloading File )9MmL-7K
T^g2N`w2
Rnt&<|8G
public SiteInfoBean() 6js94ko[
{//nSplitter的缺省值为5 8o#*0d|
//default value of nSplitter is 5 Iq0_X7:{QI
this("","","",5); asb-syqU
} *,5V;7OR
<uDEDb1|l
w'z?1M(*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #y%bx<A
{ Q( .d!CQ>
sSiteURL= sURL; J*$u
sFilePath = sPath; CdgZq\
sFileName = sName; :zdMV6s
this.nSplitter = nSpiltter; j9n3
,S E5W2a]
]\w0u7}
} "- S2${
|F[E h ~
Vd~{SS2>
public String getSSiteURL() Hq[d!qc
{ )kR~|Yn<-
return sSiteURL; /KjRB_5~q}
} )QEvV:\
h 92\1,
eBX#^
public void setSSiteURL(String value) (iM"ug2
{ g^@Kx5O\
sSiteURL = value; #3vq+mcn
} Og[NRd+
jOj`S%7
x4fl=
public String getSFilePath() ,o7aIg&_H
{ tgK$}#.*
return sFilePath; uSCF;y=1g,
} QEK,mc3
OY7\*wc:
q+f]E&':
public void setSFilePath(String value) lMz5))Rr
{ La9v97H:
sFilePath = value; ?nJ7lLQA
} ;cd{+0
Yn4c6K
8"/5Lh(
public String getSFileName() }ozlED`E
{ ;> **+ezF
return sFileName; /B)ZB})z
} H6(kxpOI\
oVutHt
gXN#<g,:^
public void setSFileName(String value) ]Aap4+s
{ E;$)Oz
sFileName = value; >y)(M(o
} Ug02G
e\x=4i
`RDlk
public int getNSplitter() P5/K?I~/So
{ d!kiWmw,
return nSplitter; BqC, -gC
} +^tq?PfE
YY-{&+,
nD6mLNi%a
public void setNSplitter(int nCount) CY;ML6c@
{ Z&FC:4!!
nSplitter = nCount; g*C&Pr3
} :acnrW>i[@
} +g,:!5pg
Gc2sY 0
S!Ue+jW
/* {|?OKCG{
**Utility.java ~l"70\&
*/ Cc*"cQe
package NetFox; vRa|lGeW
Nw ;BhBt
fD+'{ivN4
public class Utility { ^ZnlWZ@r
vw=OGjT_>m
{wMw$Fvf
public Utility() y;A<R[|Ve
{ WmU4~.
YSwAu,$jf
& V:q}Q
} 1~:7W
(\m4o
//线程睡眠 jv7-i'I@
public static void sleep(int nSecond) bK;I:JK3
{ ^|y6oj
try{ JwWW w1
Thread.sleep(nSecond); *0]E4]ZO
} 2|]$hjs
catch(Exception e) Qr]xj7\@i
{ Q4e*Z9YJ
e.printStackTrace (); H&jK|]UXoO
} L6`(YX.:
} Eyi^N0
`s#0/t
//日志 jn vJ`7zFP
public static void log(String sMsg) Jj+|>(P
{ *(6vO{
System.err.println(sMsg); wY|&qX,
} W^; wr#
-=BQVJ_dK{
.Tr!/mf_
public static void log(int sMsg) ]oB-qfbH
{ 5=%:CN!/@p
System.err.println(sMsg); ixF '-
} +F3@-A
} (t'hWS
']1\nJP[=X
q[p+OpA
/* e! V`cg0
**TestMethod.java Yqz(@( %
*/ {<0=y#@u
package NetFox; i5wXT
+U/+iI>0
%!%G\nv
public class TestMethod { \GYh"5
T0BFit6
[kwVxaI
public TestMethod() ,!+>/RlJ
{ ///xx/weblogic60b2_win.exe -w nlJi1f
try{ <#AS[Q[N
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =9$hZ c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); gwE#,OY*
SiteFileFetch fileFetch = new SiteFileFetch(bean); WE\@ArY>
fileFetch.start(); ?U'c;*O-
} pN# \
catch(Exception e){e.printStackTrace ();} zf-)c1$*r
l>K z5re^
fwaq
} !f5I.r~
d`]|i:*q
j3{8]D
public static void main(String[] args) 2eErvfC[
{ YEfa8'7R
new TestMethod(); w@&g9e6E
} ph\KTLU
} 0>hV?A
点击下载更多相关资料