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)); t2:c@)
} <d^7B9O?&w
for(int i=0;i<nEndPos.length-1;i++) P=@lkF!\#
{ Po_OQJ:bd
nEndPos = nStartPos[i+1]; <7rK
} %8tN$8P
nEndPos[nEndPos.length-1] = nFileLength; )L!R~F C
} '2tEKVb
} cg.e(@(
$SXxAS1
I5A^/=bf&
//启动子线程 10rGA=x'(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b>z.d-
for(int i=0;i<nStartPos.length;i++) s`J=:>9*
{ hq*JQb;Y}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \,EPsQV0?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), VqrMi *W6
nStartPos,nEndPos,i); P~<93
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V[M#qZS
fileSplitterFetch.start(); acZHb[w
} l!y _P
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D5>~'N3b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (0Qq rNs
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J9FNjM[qe
nEndPos = " + nFileLength); t/1NTa
// fileSplitterFetch[nPos.length-1].start(); _pGviGR
,OCTm%6e
de6dLT>m
//等待子线程结束 _e_%U<\4
//int count = 0; Sg$\ab$
//是否结束while循环 T/;hIX:R
boolean breakWhile = false; $te,\$&}
\i+h P1mz
,m?D\Pru
while(!bStop) [J`G`s!
{ F"H!CJJu&
write_nPos(); DG\YZV4
Utility.sleep(500); ])L'Rk#4
breakWhile = true; -9I%
\Sby(l
}tZAU\z
for(int i=0;i<nStartPos.length;i++) N)*e^Nfb
{ +-\9'Q
if(!fileSplitterFetch.bDownOver) P` F'Nf2U
{ ;QQ7vo
breakWhile = false; 5#)<rK
break; HdUW(FZ
} KL mB
} BznA)EK?@
if(breakWhile) grdyiBSVn
break; _ICDtG^
j~H`*R=ld#
`_A?a_[*
//count++; PJ@,01
//if(count>4) [Be53U{=
// siteStop(); "T%'Rp`j|
} p.] .M"A
AV4HX\`{P0
cu^*x/0,
System.err.println("文件下载结束！"); @!/fvP
} <57l|}8
catch(Exception e){e.printStackTrace ();} /VO@>Hoh
} _0q~s@-
8{fz0H.<?
FqxOHovE
//获得文件长度 1GE%5
public long getFileSize() nj0AO0
{ k3[h'.ps
int nFileLength = -1; 6xIYg^
try{ w a<C*o
URL url = new URL(siteInfoBean.getSSiteURL()); {U '&9_y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %Dls36F
httpConnection.setRequestProperty("User-Agent","NetFox"); 2 `h!:0
B;]5,`#!
)UZ0gfx
int responseCode=httpConnection.getResponseCode(); x5z4Yv^ m
if(responseCode>=400) ZV]e-
{ ,(27p6!
processErrorCode(responseCode); ~!-8l&C
return -2; //-2 represent access is error >DUE8hp;<
} Hq\E06S@
M|#5gKXd
Z)i1?#
String sHeader; ~1r*/@M[V
[F)/mN
62l0 Z-
for(int i=1;;i++) |id79qY7g
{ XQJ^)d00h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u%1k
//Utility.log(in.readLine()); 8C,utjy
sHeader=httpConnection.getHeaderFieldKey(i); ObyuhAR
if(sHeader!=null) ho]!G498
{ E}' d,v#Z{
if(sHeader.equals("Content-Length")) RvSq KW8
{ iQzX-a|4]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T[XP\!z]B!
break; \_Kt6=
} 9X$#x90
} uWB:"&!^
else T E&Q6
break; XBQ<
} >@^yj+k
} PWk?8dL-
catch(IOException e){e.printStackTrace ();} *Qg5Z
catch(Exception e){e.printStackTrace ();} }K/}(zuy1Y
a][pTC\rb
rbK#a)7
Utility.log(nFileLength); Z&]+A,
{y&\?'L'
mfngbFa1
return nFileLength; _(6B.
} g{v5mly
xZP>g
`\ef0
//保存下载信息（文件指针位置） ,%?; \?b%h
private void write_nPos() >'ksXA4b
{ &,N3uy;Gc
try{ 6MQs \J6.
output = new DataOutputStream(new FileOutputStream(tmpFile)); [W9e>Nsp0
output.writeInt(nStartPos.length); Tr+h$M1_Ja
for(int i=0;i<nStartPos.length;i++) \,l.p_<
{ jSie&V@px
// output.writeLong(nPos); Q7uAf3
output.writeLong(fileSplitterFetch.nStartPos); t+3
output.writeLong(fileSplitterFetch.nEndPos); H~?*KcZ 0\
} `;5VH]V
output.close(); jr,&=C(
} Ha)3i{OM
catch(IOException e){e.printStackTrace ();} GUu\dl9WA'
catch(Exception e){e.printStackTrace ();} I|KY+k> /
} !fi &@k
smfG,TI
r~$}G-g
//读取保存的下载信息（文件指针位置） p}YI#f in/
private void read_nPos() ( zn_8s
{ "UQr:/
try{ oLrkOn/aY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); AI1@-
int nCount = input.readInt(); $ \Q<K@{
nStartPos = new long[nCount]; ku/\16E/k
nEndPos = new long[nCount]; 35Ai;mU'
for(int i=0;i<nStartPos.length;i++) .'t (-eT,
{ Z/2,al\
nStartPos = input.readLong(); Js\-['`
nEndPos = input.readLong(); @sc8}"J]#
} <|{L[
input.close(); Gw ~{V
} w^06z,
catch(IOException e){e.printStackTrace ();} .S~@BI(|<
catch(Exception e){e.printStackTrace ();} K0tV'Ml#"
} Jj2g5={
;_mgiKHg
WGH%92
private void processErrorCode(int nErrorCode) ,>D ja59
{ F>(qOH.I
System.err.println("Error Code : " + nErrorCode); Mw/?wtW
} :PgF
fNmE,~
^oS$>6|
//停止文件下载 X AQGG>
public void siteStop() PT3>E5`Nu
{ _Zh2eXWdjM
bStop = true; 4bP13f
for(int i=0;i<nStartPos.length;i++) $Mdbto~<
fileSplitterFetch.splitterStop(); LtC~)R
R<"2%oY
%tT"`%(+
} %lN2n,AK
} !\QeBd+
//负责部分文件的抓取 %b=Y <v
**FileSplitterFetch.java 3(1]FKZtt
*/ b6 $,Xh
package NetFox; hS4.3]ei
dZPW2yf
!n|#|.0m
import java.io.*; EJ1Bq>u7
import java.net.*; >BBl7
?#d6i$
&|)hCJu
public class FileSplitterFetch extends Thread { 4w'lu"U
Ve)ClH/DW
+wipfL~&S
String sURL; //File URL lK0s=4c{
long nStartPos; //File Snippet Start Position @&;(D!_&
long nEndPos; //File Snippet End Position NwguP
int nThreadID; //Thread's ID *P`v^&
boolean bDownOver = false; //Downing is over 2z4<N2!M
boolean bStop = false; //Stop identical X:>$8^gS
FileAccessI fileAccessI = null; //File Access interface "jT#bIm
:pRF*^eU
cgyp5\*>+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ny)]GvxI
{ hR-K@fS%l'
this.sURL = sURL; $*k)|4
this.nStartPos = nStart; c7\VTYT
this.nEndPos = nEnd; GD!- qH
nThreadID = id; #<4--$Xo
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /#f^n]v
} NetYg]8`
Y(_KizBY
JBz}|MD
public void run() KF+mZB
{ um7o!yg,
while(nStartPos < nEndPos && !bStop) B@ {&<
{ ^-hErsK
/prYSRn8
C ZJV_0
try{ u^=`%)
URL url = new URL(sURL); B8H75sz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *:g_'K"+
httpConnection.setRequestProperty("User-Agent","NetFox"); PnA?+u2m
String sProperty = "bytes="+nStartPos+"-"; 8u>gbdU
httpConnection.setRequestProperty("RANGE",sProperty); dy2rkV.z
Utility.log(sProperty); =LI:S|[4
R(G\wqHUT3
_1aGtX|W
InputStream input = httpConnection.getInputStream(); x0A7O
//logResponseHead(httpConnection); /_)l|<k+V
IxOc':/jY
)1lu=gc
byte[] b = new byte[1024]; zC=a3
int nRead; ^ q?1U?4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) je%ldY]/@
{ UX2lPgKdLz
nStartPos += fileAccessI.write(b,0,nRead); hJf2o
//if(nThreadID == 1) E=AVrv5T
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jZd}OC<
} n*<v]1
.po>qb6
o_f-GO
Utility.log("Thread " + nThreadID + " is over!"); e\F}q)_
bDownOver = true; G>w+#{(
//nPos = fileAccessI.write (b,0,nRead); F}36IM9/:
} o5!f#Y
catch(Exception e){e.printStackTrace ();} hi|!
} c7K!cfO:{N
} m|O1QM;T
;JT(3yK4>p
zXZir7NfM
//打印回应的头信息 U%>'"
public void logResponseHead(HttpURLConnection con) _Zc4=c,K
{ O,s.D,S
for(int i=1;;i++) P|xG\3@Z
{ O)]v;9oER
String header=con.getHeaderFieldKey(i); Xgat-cy'DA
if(header!=null) [&#/|zH'j:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =sgdkAYwP
Utility.log(header+" : "+con.getHeaderField(header)); q/PNJ#<
else lr~0pL
break; $4m*kQ
} $SY]fNJQ
} 8Lz]Z h=ZU
B{MaMf)
V5p0h~PK
public void splitterStop() jVWK0Zba
{ qf#)lyr<D6
bStop = true; poT&-Ic[
} (=u'sn:s
2eb1lJdS
3<:jx~y>
} eSfnB_@x2
Y@uh[aS!
)C~9E 5E
/* Q@S-f:!
**FileAccess.java e,0-)?5R
*//文件访问(定位，写) 3n]79+w@z
package NetFox; * F4UAQzYb
import java.io.*; nP3 E
UvJ;A
j:,9%tg
public class FileAccessI implements Serializable{ 91Z'
Vzg=@A#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O_~7Glu
RandomAccessFile oSavedFile; Yh<WA>=
long nPos; -_N)E ))G
;9a 6pz<
,$lemH1d
public FileAccessI() throws IOException i=S~(gp
{ vB0RKk}d5
this("",0); L]%l51U
} `3cCH
uLR<FpM
vB'>[jvA|
public FileAccessI(String sName,long nPos) throws IOException 6%Mt
{ 12UD19!
oSavedFile = new RandomAccessFile(sName,"rw"); m Y,|J\w@
this.nPos = nPos; v,@F|c?_S
oSavedFile.seek(nPos); ?-)I+EAnE
} Na{Y}0=^y
>ut" OL9J
}baR5v
public synchronized int write(byte[] b,int nStart,int nLen) UL$}{2N,_
{ j<<3Pr
int n = -1; `G9 l
try{ 5GzFoy)j>
oSavedFile.write(b,nStart,nLen); 3FE(}G
n = nLen; zp}eLm:=d
} zeb=8Dg :
catch(IOException e) tq1CwzRX
{ > L2HET
e.printStackTrace (); _}xd}QW
} I:cg}JZ>|
i1lBto[
S$,'Q^~K
return n; u\yVR$pQ
} w;6bD'.>;
Lh.b5Q|
M5357Q
} NPa\Cg[
co8"sz0(U
').}Nz
/* tBbOY}.VD
**SiteInfoBean.java yw-8#y
*/ r!1D*v5&:
package NetFox; %EbPI)yY3
~^jq(:d)
CNZz]H
public class SiteInfoBean { Q4*?1`IsR
ElhRF{R
@gC=$A#
private String sSiteURL; //Site's URL -VKS~{
private String sFilePath; //Saved File's Path #DU26nCL
private String sFileName; //Saved File's Name TfYVw~p_%
private int nSplitter; //Count of Splited Downloading File soA|wk\A
)Z 9E=%
8Me:Yp_Xt
public SiteInfoBean() PXzsj.
{//nSplitter的缺省值为5 |1b_*G4|
//default value of nSplitter is 5 yZr M.%V
this("","","",5); >{gPN"S"a
} S8[=S
Dl(3wgA
K_)eWf0a
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i':ydDOOHA
{ 58\&/lYW
sSiteURL= sURL; XR2~Q)@
sFilePath = sPath; TxjYrzC
sFileName = sName; `*", <
this.nSplitter = nSpiltter; 6tHO!`}1
M5nWVK7c
B~]5$-
} Qd}m`YW-f$
)a9 ]US^
DI+]D~N
public String getSSiteURL() d@`M CchCB
{ JWvjWY2+P
return sSiteURL; wN1niR'
} |8>3`w!
[[PEa-992
poGc a1
public void setSSiteURL(String value) IG)s^bP
{ ;c~cet4
sSiteURL = value; S#)Eom?V
} @k[R/,#'[t
F<>!kK/c
B~o\+n
public String getSFilePath() wW>zgTG
{ xh7cVE[UM
return sFilePath; f` =CpO*
} _XJ2fA )
jK \T|vGJa
x~xa6
public void setSFilePath(String value) VE+IKj!VG0
{ &%})wZ+Dj
sFilePath = value; m'P1BLk
} l^ZI* z7N
/VmR<C?h
R\o<7g-|
public String getSFileName() yFDv6yJ.
{ m_?d=o
return sFileName; MZ Aij
} R|O8RlH
u[nyW3MZ
6qcO?U
public void setSFileName(String value) @-UL`+
{ .>Ljnk
sFileName = value; DXz}YIEC
} >:D j\"o
]|`Cuc
*`ZH` V
public int getNSplitter() 64hk2a8
{ Q+g!V5'
return nSplitter; b Q]/?cCYV
} 2M#r]
:Ad&$eg+
t#q<n:WeYU
public void setNSplitter(int nCount) 9U$EJN_G
{ ^i:`ZfA#
nSplitter = nCount; (aD_zG=k5
} 5:'hj$~|\1
} B}PIRk@a1
K~@Mg1R
'1M7M(va
/* 0eK*9S]
**Utility.java W5SJ^,d)J
*/ |V<h=D5W
package NetFox; 035rPT7-2-
v|U(+O
ZDbc
public class Utility { rn<PR*
#1>X58I^
r*Yi1j/
public Utility() }Ho Qwy|&
{ >JiltF7H0
sQMFpIrr
**}h&k&%2
} ,3@#F/c3i~
In`mtn q
//线程睡眠 `w]s;G[
public static void sleep(int nSecond) y@\V+
{ c%=IL M4
try{ qWmQ-|Py
Thread.sleep(nSecond); YW{C} NA
} N^3N[lD{
catch(Exception e) Fd0%lnui
{ P*cNh43U
e.printStackTrace (); ;[fw]P n
} s`0QA!G{-
} rF]h$Z8o
qh`t-
//日志 \Ym5<];E
public static void log(String sMsg) F7Zwh5W
{ ,_Z+8
System.err.println(sMsg); j?MAED
} By%=W5
3-&QRR#p
Q=]w !I\
public static void log(int sMsg) !Y-98<|b M
{ |+T1XYG5
System.err.println(sMsg); ztw@Y|<2
} V O3x~E
} z<yU-m2h
q5?# 3T=
JU4qzi
/* ^k]XEW{PG
**TestMethod.java l8?>>.<P=
*/ 2$Tj84'X
package NetFox; #5f-`~^C{
M@5?ZZ4L
f"<O0Qw
public class TestMethod { xP[n
ONe# rKJ_
^k9kJ+x^S2
public TestMethod() K"r*M.P>
{ ///xx/weblogic60b2_win.exe X-wf:h?i
try{ ?]*^xL;x?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kkQVNphc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }I :OsAw
SiteFileFetch fileFetch = new SiteFileFetch(bean); XHK70: i
fileFetch.start(); ^/r7@:
} m@^1JlH
catch(Exception e){e.printStackTrace ();} -?0qf,W.
yxH ( c
?Orxmxc 2
} t2lS ~l)
RO.k]x6
Bro9YP4<
public static void main(String[] args) B&@?*^.
{ oZAB_A)[-
new TestMethod(); 9^j &VmF
} !P-^O
} IP(Vr7-v
点击下载更多相关资料