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)); J ?0P{{
} RNo~}#
for(int i=0;i<nEndPos.length-1;i++) K+\2cf?bU
{ XEBeoOX/
nEndPos = nStartPos[i+1]; 6bDizS}
} O70#lvsM;
nEndPos[nEndPos.length-1] = nFileLength; 8S` j6
} }U'VVPh_
} mY[*(a
RkZyqt @+
-}1TT@
//启动子线程 z3c7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8 =oUE$9
for(int i=0;i<nStartPos.length;i++) 11vAx9
{ 1'!D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'gtcy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3#?53s
nStartPos,nEndPos,i); Tb:6IC7="
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G<-<>)zO!
fileSplitterFetch.start(); Zi?:< H}
} Ft^X[5G4L
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O\SH;y,N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a/</P |UG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F/PH=Dk
nEndPos = " + nFileLength); LJ6L#es2
// fileSplitterFetch[nPos.length-1].start(); iR"6VO
D*>#]0X
Jj/}GVNc7
//等待子线程结束 #KNl<V+c}1
//int count = 0; nYR#Q|
//是否结束while循环 Z~w2m6;s
boolean breakWhile = false; -'F27])
LzxO=+=9!q
DheQcM
while(!bStop) &e78xtA{
{ 5Bt~tt
write_nPos(); W] WH4.y
Utility.sleep(500); b0/YX@
breakWhile = true; ;b(ww{&
t,n2N13
xs&xcRR"
for(int i=0;i<nStartPos.length;i++) (xE |T f
{ \H9:%Tlp~4
if(!fileSplitterFetch.bDownOver) a`8]TD
{ artn _
breakWhile = false; F9Af{*Jw?x
break; FQ>kTm`d
} :+ mULUi
} 9Z }<H/q
if(breakWhile) QJ(5o7Tfn
break; 6Xz d>5x
0@[*~H0{n
r \[|'hA
//count++; r{B28'f[
//if(count>4) ?pcbso
// siteStop(); *o38f>aJl
} [2YPV\=
'<xE0<
&4+|{Zx0
System.err.println("文件下载结束！"); [V>s]c<4`o
} m)LI| v
catch(Exception e){e.printStackTrace ();} ZJenwo
} {6WG
V2|By,.
/G|v.#2/g
//获得文件长度 Te[v+jgLY,
public long getFileSize() VdGVEDwz
{ AorY#oq
int nFileLength = -1; .k-6LR
try{ 3y+~l H:
URL url = new URL(siteInfoBean.getSSiteURL()); 3tCTPZy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wP*3Hx;S
httpConnection.setRequestProperty("User-Agent","NetFox"); C #iZAR
M.6uWwzQR
sQj]#/yK:
int responseCode=httpConnection.getResponseCode(); _"Z?O)d*
if(responseCode>=400) N$=9R
{ Y<u%J#'[
processErrorCode(responseCode); LT Pr8^
return -2; //-2 represent access is error Pc=ei
} Nf<f}`
!'~Ldl
ap'La|9t>
String sHeader; tW4X+d"
rdd-W>+
Igmg&
for(int i=1;;i++) vanV|O
{ Sh1$AGm
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;"u,G!
//Utility.log(in.readLine()); k(pJVez
sHeader=httpConnection.getHeaderFieldKey(i); pi~5}bF!a
if(sHeader!=null) R6BbkYWrX
{ dQ7iieT
if(sHeader.equals("Content-Length")) R.*;] R>M
{ zn 0y`9!n?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7Y[ q)lv
break; xjiV9{w
} %hN>o)
} \1gAWUt('
else wW p7N
break; :d9GkC
} >;1w-n
} f.uuXK
catch(IOException e){e.printStackTrace ();} ] 1pIIX}
catch(Exception e){e.printStackTrace ();} D.:`]W|
u-|%K.A
\t1#5
Utility.log(nFileLength); x%r$/=
eu"m0Q
lY"l6.c
return nFileLength; ~EY)c~H
} @,eo*
T@.+bD
U5N|2
//保存下载信息（文件指针位置） M&V4|D
private void write_nPos() J)B3o$
{ hWbu Z%
try{ DJgM>&Y6,
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^i#0aq2}
output.writeInt(nStartPos.length); -s2)!Iko&
for(int i=0;i<nStartPos.length;i++) Bj2iYk_cLa
{ g2TK(S|#
// output.writeLong(nPos); eA(\#+)X `
output.writeLong(fileSplitterFetch.nStartPos); /nA>ox78
output.writeLong(fileSplitterFetch.nEndPos); NR(rr.
} FT~c|ep.
output.close(); ?>*d82yO
} %A~. NNbS
catch(IOException e){e.printStackTrace ();} _ps4-<ugC
catch(Exception e){e.printStackTrace ();} 5)S;R,
} jrN 5l1np
p gLhxc:
cJq{;~
//读取保存的下载信息（文件指针位置） eWm'eO
private void read_nPos() !gLJBp
{ Z"Hq{?l9
try{ <ZZfN@6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eyDI>7W
int nCount = input.readInt(); .aa7*e
nStartPos = new long[nCount]; p%>!1_'(
nEndPos = new long[nCount]; {`2 0'
for(int i=0;i<nStartPos.length;i++) "7+^`?
{ E{JTy{z-
nStartPos = input.readLong(); tQ;Fgv8Y!
nEndPos = input.readLong(); 4%nK0FAj
} \)\n5F:Zu
input.close(); l>`S<rGe
} !K*3bY`#
catch(IOException e){e.printStackTrace ();} 4jZt0
catch(Exception e){e.printStackTrace ();} d:&cq8^
} v8E:64
]A-LgDsS
78xiT
private void processErrorCode(int nErrorCode) 5C`Vno~v
{ \J(~ Nv5!
System.err.println("Error Code : " + nErrorCode); ]OKKR/:
} JK^%V\m
f~=e
l3MA&&++KF
//停止文件下载 C&d,|e "\
public void siteStop() ?=iy 6q
{ PB8U+
bStop = true; x51p'bNy
for(int i=0;i<nStartPos.length;i++) ^JIs:\g<<
fileSplitterFetch.splitterStop(); }FV_jJ
\@ZD.d#
S,+|A)\#
} }darXtZKkK
} 9WoTo ,q
//负责部分文件的抓取 =x^IBLHN
**FileSplitterFetch.java xWQQX
*/ :Z;kMrU
package NetFox; q4/P'.S
Fok`-U
i"!j:YEo
import java.io.*; gavf$be
import java.net.*; r`0oI66B/
#{bT=:3a
Y5IQhV.
public class FileSplitterFetch extends Thread { 3XjY
Vc|QW
?y*yl
String sURL; //File URL J72kjj&C
long nStartPos; //File Snippet Start Position hdH-VR4
long nEndPos; //File Snippet End Position ''EFh&F
int nThreadID; //Thread's ID 5Obv/C
boolean bDownOver = false; //Downing is over `@ Ont+
boolean bStop = false; //Stop identical <M3&\
FileAccessI fileAccessI = null; //File Access interface #|l#
<^A1.o<GN
eNt1P`2[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7tT L,Nxe
{ cC`PmDGq
this.sURL = sURL; 6CWm;%B#G
this.nStartPos = nStart; ;&RHc#1F
this.nEndPos = nEnd; H]f8W]"c[
nThreadID = id; 7}e{&\0=l
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2I~a{:O
} UbwD2>
oJ}$ /_
/{X2:g{
public void run() QW@`4W0F
{ {D8[pG%z
while(nStartPos < nEndPos && !bStop) 0R?LWm j
{ '%A*Z,f
EtvYIfemr
Zo5.Yse
try{ mt3j$r{_
URL url = new URL(sURL); cf1GA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?pF uV`Zm
httpConnection.setRequestProperty("User-Agent","NetFox"); > 1&_-
String sProperty = "bytes="+nStartPos+"-"; 7 S2QTRvH
httpConnection.setRequestProperty("RANGE",sProperty); Gl>_C@n0h
Utility.log(sProperty); P"mD73a
{B lM<
vwQ6=
InputStream input = httpConnection.getInputStream(); ! .|\}=[e
//logResponseHead(httpConnection); Bl)DuCV
wi/dR}*A
R~DZY{u+/$
byte[] b = new byte[1024]; 9i+SU|;j
int nRead; 9AdA|/WV
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) J'>i3eLq
{ f"G?#dW/1
nStartPos += fileAccessI.write(b,0,nRead); a5xp[TlXn.
//if(nThreadID == 1) ,] ,dOIOwn
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ENi@R\ p
} zcNv T
^8yhx-mgb
WwM/M!98J
Utility.log("Thread " + nThreadID + " is over!"); YAf`Fnmw
bDownOver = true; Xm2p<Xu8h
//nPos = fileAccessI.write (b,0,nRead); k9<P]%
} *^&2L,w
catch(Exception e){e.printStackTrace ();} "R/Xv+;
} sh%snLw
} )tyhf(p6
-q.tU*xf'
%kJ_o*"
//打印回应的头信息 AG$S;)Yl9c
public void logResponseHead(HttpURLConnection con) ^l4=/=RR
{ "NamP\hj
for(int i=1;;i++) ]D;X"2I2'b
{ 8&"@6/)[
String header=con.getHeaderFieldKey(i); (0T6kD
if(header!=null) SGREpOlJ+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X^U)j N2
Utility.log(header+" : "+con.getHeaderField(header)); CcZ\QOet&C
else Ol~jq;75
break; +JMB98+l
} [y}0X^9,E
} (*Jcx:rH
H7KcPN(0
.'y]Ea
public void splitterStop() (gv1f
{ 8_S<zE`Ha
bStop = true; ~EVD NnHEr
} p<2A4="&
6mnj!p]3
\lnpsf
} w34&m
;L5'3+U
,[lS)`G
/* gm63dE>
**FileAccess.java CVh^~!"7j
*//文件访问(定位，写) X/_e#H0
package NetFox; v:MJF*/
import java.io.*; #4ZDY,>Xi#
"0F =txduS
06 kjJ4
public class FileAccessI implements Serializable{ gF@51K
CF`tNA3fxm
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `,mE '3&
RandomAccessFile oSavedFile; ]OE{qXr{
long nPos; #-ioLt%
\>8"r,hG|
T>l=0a #
public FileAccessI() throws IOException Vj7(6'Hg
{ (%huWW j
this("",0); em
} A#gmKS<J/7
}xx[=t=nUf
Ds4n>V,o
public FileAccessI(String sName,long nPos) throws IOException :xitV]1.
{ 6% @@~"
oSavedFile = new RandomAccessFile(sName,"rw"); qNP&f8fH
this.nPos = nPos; _7(>0GY
oSavedFile.seek(nPos); (Yz EsY
} .z u0GsU=
[:x^ffs
*Z! #6(G
public synchronized int write(byte[] b,int nStart,int nLen) Y%v?ROql
{ #>+O=YO
int n = -1; #/NZ0IbHk
try{ NPws^
oSavedFile.write(b,nStart,nLen); KJPCO0"
n = nLen; U^trZ])
} 6b9 oSY-8
catch(IOException e) &>UI{
{ 6Y^UC2TBs
e.printStackTrace (); _RT3Fk
} xEN""*Q
e_Na_l]
UD|Qa
return n; [hs_HYqJ
} ]iewukB4
pp$WM\r
h:iK;
} gF(aYuk
99%oY
0xbx2jlkY
/* 8OoKP4,;
**SiteInfoBean.java R}MdBE
*/ VG*Tdaua~
package NetFox; 0|g|k7c{rF
vT)(#0>z
V!#+Ti/w4
public class SiteInfoBean { .i[rd4MCK
~^((tT
x8I=I"Sp
private String sSiteURL; //Site's URL Az.(tJ X"
private String sFilePath; //Saved File's Path {-*+G]
private String sFileName; //Saved File's Name '_& Xemz
private int nSplitter; //Count of Splited Downloading File tz&'!n}
~1xln?Q
!+tz<9BBY
public SiteInfoBean() {ndL]c'v
{//nSplitter的缺省值为5 RIBj9kd
//default value of nSplitter is 5 ydo"H9NOS
this("","","",5); (q'w"qj
} EoM}Co
G8%Q$
{3@lvoDT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gqR?hZD
{ dI'cZt~n
sSiteURL= sURL; O,(p><k$/
sFilePath = sPath; Fm(~Vt;%u
sFileName = sName; #L[-WC]1y
this.nSplitter = nSpiltter; o@TxDG
B{'x2I#,
b0 ))->&2
} NZ:A?h2JR
RD_IGV
7Io]2)V
public String getSSiteURL() AfmGA9
{ C2RR(n=N^
return sSiteURL; dIiQ^M
} 8&FnXhZg4
N yT|=`;
JBa( O-T
public void setSSiteURL(String value) fpbb <Ro
{ :A%|'HxH3
sSiteURL = value; Sc Uh -y_
} k2Yh?OH
,H!E :k
=fmM=@!$<
public String getSFilePath() dKyJ.p
{ Kn~f$1
return sFilePath; %_xRS
} )G$/II9d
t,#9i#q#
ycAQHY~n
public void setSFilePath(String value) $_s"16s
{ 9?c0cwP?
sFilePath = value; 69{^Vfd;Y
} Y<%)Im6v/
7\*_/[B
P,y*H_@k
public String getSFileName() "N'tmzifh
{ ] h3~>8<
return sFileName; Oga/
} L&3Ak}sh
K=x>%6W7b
,!U._ic'B
public void setSFileName(String value) ;Awt:jF
{ ,Bh!|H(?L1
sFileName = value; XOsPKq
} $j61IL3+
wc7gOrPpm
M0[7>N_
public int getNSplitter() oNHbQ&h
{ f7B)iI!
return nSplitter; SV%;w>
} },9Hq~TA
`I|$U)'
&DoYz[q
public void setNSplitter(int nCount) _U}pdzX?
{ ismx evD
nSplitter = nCount; ciRn"X=l
} /VFh3n>I2
} ``*iK
];& @T\Rj
'Rbv3U
/* ziUEA>m*/
**Utility.java #-S%aeB
*/ o6LeC*
package NetFox; wc?`QX}I
64]_o/u5W4
%M"rc4Xd
public class Utility { \\Ps*HN
A")F7F31c
zN2CI6
public Utility() Z$qLY<aV
{ +T]/4"^M
a<%Ivqni
J~.8.]gXW
} MTm}qx@L
z%ZAN-
//线程睡眠 +<#0V!DM
public static void sleep(int nSecond) X2CpA;#;7l
{ ^{f^%)X
try{ WdQR^'b$
Thread.sleep(nSecond); S\$=b_.
} XMt)\r.
catch(Exception e) a=m4)tjk
{ D^]g`V*N
e.printStackTrace (); .%~m|t+Rt
} 0?@;zTE0
} =$kSvCjP
h=<x%sie
//日志 MaMP7O|W
public static void log(String sMsg) C/34K(
{ e`]x?t<U4/
System.err.println(sMsg); pZeJ$3@vk
} @\ udaZc
/6Bm <k%
r.WQ6h/eZ5
public static void log(int sMsg) B!J~ t8
{ o8uak*"{
System.err.println(sMsg); 6*W7I-A
} t4Q&^AC
} 2~ [
t,D7X1W
E@.daUoB
/* GXk]u
**TestMethod.java &/+LY_r'<I
*/ OSu/!Iv\
package NetFox; ;W~H|M
zCz"[9k
$I*<gn9
public class TestMethod { pB(|Y]3A
l&JV.}qGB8
V*d@@%u**
public TestMethod() z^,P2kqK_
{ ///xx/weblogic60b2_win.exe uW 7Yem&
try{ {JGXdp:SB
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K=K]R01/o
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _keI0ML-#
SiteFileFetch fileFetch = new SiteFileFetch(bean); u{J\X$]
fileFetch.start(); }uFV\1
} (fqU73
catch(Exception e){e.printStackTrace ();} 3[*x'"Q;H
~pt#'65}:
Pl/B#Sbf'
} mb GL)NI
Y@l>4q")
M&SY2\\TB
public static void main(String[] args) *L{^em#b
{ 5>\Lk>rI
new TestMethod(); ]^>RBegJBO
} JTcE{i
} P[K42mm
点击下载更多相关资料