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)); bes<qy
} 4M^=nae
for(int i=0;i<nEndPos.length-1;i++) oxr#7Ei0d
{ yyR0]NzYUD
nEndPos = nStartPos[i+1]; pk>^?MO
} IWk4&yHUAu
nEndPos[nEndPos.length-1] = nFileLength; Lk|hQ
} !zBhbmlKt
} \h+AXs<j
JX<)EZ!F
&g#@3e1>
//启动子线程 }?lrU.@zg
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sm9k/(-
for(int i=0;i<nStartPos.length;i++) _qU4Fadgm
{ C=-=_>Q,L<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3W V"U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zlyS}x@p
nStartPos,nEndPos,i); 3Nl <p"=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p$O.> [
fileSplitterFetch.start(); 3N8t`N
} zh%#Y_[R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PoNi"Pv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9q)Kfz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CZ8KEBl
nEndPos = " + nFileLength); \TIT:1
// fileSplitterFetch[nPos.length-1].start(); ]{!U@b
eFipIn)b
bT</3>+C
//等待子线程结束 /Jta^Bj
//int count = 0; Y&`=jDI
//是否结束while循环 W'els)WJ|x
boolean breakWhile = false; hC:n5]K
JR'
q~ tz? T_
while(!bStop) 88Ey12$
{ 6e(Qwt
write_nPos(); xP_cQwm`1
Utility.sleep(500); a@8v^G
breakWhile = true; `Nv=B1
w}L]X1#sF
Y2|#V#
for(int i=0;i<nStartPos.length;i++) 3s5z UT;
{ RPwbTAl}
if(!fileSplitterFetch.bDownOver) C,wL0Yj[
{ 0;hqIJcE:\
breakWhile = false; >f^r^P
break; Y1L[;)Hn
} Uq[>_"}
} uyO/55;HO
if(breakWhile) f0A{W/0n
break; 'SO %)B
:8I9\eet3
9FoHD
//count++; vGvf<ra;H
//if(count>4) ^/)^7\@
// siteStop(); d^@dzNv
} @#<D ^"
Wfu(*
'>NCMB{*
System.err.println("文件下载结束！"); 7jxslI&F
} ?:pP8/y
catch(Exception e){e.printStackTrace ();} 0\H\lKcK
} |<HPn4 ,X
wYdb*"R
QFE:tBHe
//获得文件长度 6O|@xvg
public long getFileSize() oOnop-z7
{ .RE:;<|w
int nFileLength = -1; 2^Eg9y'
try{ fA&k`L(y
URL url = new URL(siteInfoBean.getSSiteURL()); k@\ iGqo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VX].3=T8
httpConnection.setRequestProperty("User-Agent","NetFox"); >i_2OV
j@=%_^:i
R}'bP
int responseCode=httpConnection.getResponseCode(); R(!s
if(responseCode>=400) UXeN8
{ ;"KJ7p
processErrorCode(responseCode); mkMq
return -2; //-2 represent access is error yu;+o3WlK
} t!*?dr
kv]~'Srk
Z"Zmo>cV4
String sHeader; 3Ko/{f
hM@ HA
|pm7_[
for(int i=1;;i++) pyH:#5
{ O&vVv _zh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?*2CpM&l
//Utility.log(in.readLine()); &?W0mW(
sHeader=httpConnection.getHeaderFieldKey(i); 2I%MAb&1@
if(sHeader!=null) %;cddLQ\xY
{ %.vQU @2A
if(sHeader.equals("Content-Length")) .nB0 h
{ 83E7k]7]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uya.sF0]9B
break; ;l4[%xld
} #G.ulX
} 3%l*N&gsg:
else ]@dZ{H|
break; ?b*s. ^
} }]e-{C}
} ?Fi=P#
catch(IOException e){e.printStackTrace ();} ]|!OP
catch(Exception e){e.printStackTrace ();} F{Z~ R
}e!x5g
N+++4;
Utility.log(nFileLength); ! _f9NK
YT8vP~
5}:-h>
return nFileLength; ?u-|>N>
} :S.9eFfa
OJ,`
j`oy`78O
//保存下载信息（文件指针位置） YHkn2]^#A
private void write_nPos() K:!"+q
{ W6f/T3
try{ !5.8]v
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,X#2\r<|
output.writeInt(nStartPos.length); V}bjK8$$
for(int i=0;i<nStartPos.length;i++) ?/BqD;{?I
{ #EO9UW5
// output.writeLong(nPos); _ <WJ7
output.writeLong(fileSplitterFetch.nStartPos); 0F]>Jby
output.writeLong(fileSplitterFetch.nEndPos); 'L 8n-TyL
} @GkILFN
output.close(); _hN\10ydY
} c0PIc^R(@
catch(IOException e){e.printStackTrace ();} 1|RANy
catch(Exception e){e.printStackTrace ();} os,* 3WO
} ~kShq%
cU;iUf
|y&*MTfV4L
//读取保存的下载信息（文件指针位置） J]v%q,"
private void read_nPos() [p{#XwN
{ &Nj3h(Ll
try{ (}a8"]Z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); { D^{[I
int nCount = input.readInt(); xGu r
nStartPos = new long[nCount]; H(bs$C4F
nEndPos = new long[nCount]; V@Rrn <l
for(int i=0;i<nStartPos.length;i++) b6}H$Sx~
{ |rJ=Ksc
nStartPos = input.readLong(); _(Sa4Vb=Q6
nEndPos = input.readLong(); .l>77zM6
} @{YS}&Q/
input.close(); ?!9)q.bW
} iTFdN}U
catch(IOException e){e.printStackTrace ();} "{tg8-a4)
catch(Exception e){e.printStackTrace ();} TatpXN\
} (&}i`}v_
s~>d:'k7|
2Or'c`|
private void processErrorCode(int nErrorCode) bu |a0h7e
{ vI2^tX9
System.err.println("Error Code : " + nErrorCode); x$IX5:E#e
} '$|[R98
V^JV4 `o
Z3{>yYR+
//停止文件下载 ~Q?a|mV,
public void siteStop() g6Q!8
{ lL{5SH<Q
bStop = true; >H'4{|
for(int i=0;i<nStartPos.length;i++) {U!8|(
fileSplitterFetch.splitterStop(); o=21|z
fJ/e(t
])L A42|
} ?0)&U
} Tsgk/e9K2?
//负责部分文件的抓取 l7W 6qNB
**FileSplitterFetch.java G]fRk^~
*/ >;L6xt3
package NetFox; '@p['#\uI
Fb^:V4<T
WpF2)R}G=
import java.io.*; x*?x=^I{
import java.net.*; #gp,V#T
MKy[hT:
zY,r9<I8_x
public class FileSplitterFetch extends Thread { %1O;fQL
p$h4u_
_h X]%
String sURL; //File URL ;cPy1
long nStartPos; //File Snippet Start Position >)spqu]
long nEndPos; //File Snippet End Position AI,(z;{P
int nThreadID; //Thread's ID Sg6"WV{<
boolean bDownOver = false; //Downing is over V#cqRE3XNi
boolean bStop = false; //Stop identical x/;buW-
FileAccessI fileAccessI = null; //File Access interface UG)8D5
y>72{
W0epAGrB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2'_:S@
{ Fb7#<h
this.sURL = sURL; TQx.KM>y
this.nStartPos = nStart; IG|X!l
this.nEndPos = nEnd; o3I Tr';
nThreadID = id; fRtUvC-#H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O)ME"@r@:
} `t_W2y
,!dh2xNH^
j:E<p_T
public void run() +RnkJ* l
{ J(c{y]`J
while(nStartPos < nEndPos && !bStop) YN`H BFH
{ ~v]!+`_J
cfcim.jB
_Y8hb!#(
try{ po$ /7
URL url = new URL(sURL); O [i#9)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JMH8MH*
httpConnection.setRequestProperty("User-Agent","NetFox"); TiYnc3Bz}J
String sProperty = "bytes="+nStartPos+"-"; >TQH|}|6(y
httpConnection.setRequestProperty("RANGE",sProperty); +m8!U=Zi
Utility.log(sProperty); &_~+(
PI`jExL
q{t*34R
InputStream input = httpConnection.getInputStream(); NX|v=
//logResponseHead(httpConnection); [k6nW:C
[ { bV4
mnmP<<8C,
byte[] b = new byte[1024]; =$nB/K,8AX
int nRead; .G+Pe'4a
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M@?xa/E64
{ p;W.lcO`0
nStartPos += fileAccessI.write(b,0,nRead); DdVF,
//if(nThreadID == 1) :,J}z~I,lB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); agjv{
} [1F*bI
'ow.=1N-
Yc,7tUz#
Utility.log("Thread " + nThreadID + " is over!"); Y7vA`kjD-C
bDownOver = true; Sh?4ri@:
//nPos = fileAccessI.write (b,0,nRead); _cc#Qlw 7
} sVJ!FC
catch(Exception e){e.printStackTrace ();} ~-PjW#J%
} :cGt#d6
} {K9/HqH
_>9.v%5cs(
Eh|]i;G%
//打印回应的头信息 ,(;lIP
public void logResponseHead(HttpURLConnection con) 3:8{"md@2
{ P&b19K'
for(int i=1;;i++) nS&3?lx9_
{ j{NNSi3
String header=con.getHeaderFieldKey(i); /Wy.>YC|
if(header!=null) 'Er:a?88l
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z}{afEb
Utility.log(header+" : "+con.getHeaderField(header)); #{=;NuP
else x-?{E
break; :PtF+{N>
} 7{I h_.#
} 1[jb)j1
(y M^
BM(]QUxRd
public void splitterStop() '3<fsK=
{ +reor@h
bStop = true; ~i21%$
} v@wb"jdFi$
[+OnV&
D<V~f B
} =e8bNg
2'5]~
vq!_^F<
/* 7f~Sf
**FileAccess.java _L@2_#h!
*//文件访问(定位，写) ,2j.<g&
package NetFox; 5vw{b?
import java.io.*; ^|TG$`M(w
xCYE B}o9r
i:Zm*+Gi
public class FileAccessI implements Serializable{ $2u 'N:o
WdnIp!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JqMDqPIQ
RandomAccessFile oSavedFile; %zSuK8kxV
long nPos; fwBRWr9
OX"j#
Dgx8\~(E'
public FileAccessI() throws IOException J]q%gcM
{ %~jkB.\* )
this("",0); n_B"-n
} P9S2?Q
|QMhMGjV
V=lfl1Ev0J
public FileAccessI(String sName,long nPos) throws IOException *bxzCI7b
{ > ]8a3x
oSavedFile = new RandomAccessFile(sName,"rw"); "3<da*D1
this.nPos = nPos; Zr-U&9.`
oSavedFile.seek(nPos); JR@.R ,rII
} j~FD{%4N
STglw-TC\
3LfC{ER
public synchronized int write(byte[] b,int nStart,int nLen) in(U:04
{ uio@r^Xz
int n = -1; KL ?@@7
try{ :Dd$i_3=
oSavedFile.write(b,nStart,nLen); +n7?S~R$
n = nLen; l27\diKPJ
} TuW/N L|
catch(IOException e) 6:]*c[7
{ 06Gt&_Q
e.printStackTrace (); ;A'":vXmc
} }=v)Js
f}L*uw
0v]?6wX
return n; 4&HXkRs:
} b9"jtRTdz
>/#KI~}'N
_ib"b#
} #BQ.R,
$z$u{
4]/7 )x?R
/* p2N:;lXM
**SiteInfoBean.java I(S)n+E
*/ 0x9x@gF
package NetFox; iA,kX\nK
>OP+^^oZ<
f"(X(1F
public class SiteInfoBean { c5Q<$86
&|aqP \Q5
i[ $0a4
private String sSiteURL; //Site's URL >5wx+n)/)
private String sFilePath; //Saved File's Path fi+R2p~vs
private String sFileName; //Saved File's Name ~h"/Tce
private int nSplitter; //Count of Splited Downloading File 5"/J^"!h
.7 asW(
*c)uGz'cD
public SiteInfoBean() /1 RAAa
{//nSplitter的缺省值为5 \V>?Do7
//default value of nSplitter is 5 +`sv91c
this("","","",5); gt\MS;jMa
} :d8W+|1u
cv(PP-'\
Q.Aw2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <jS~ WI@
{ 5~.ZlGd
sSiteURL= sURL; unJ R=~E
sFilePath = sPath; 0A:n0[V:]
sFileName = sName; fGv#s X
this.nSplitter = nSpiltter; zFQ&5@43
Q`#4W3-,
!;Jmg
} cD4 kC>P*
TM8=U-A
huudBc A[
public String getSSiteURL() 5`]UE7gT
{ nr)c!8
return sSiteURL; 63!rUB!
} ?+c`]gO7N
~O 3D[PNW~
UA~RK2k?
public void setSSiteURL(String value) {"vkji>
{ W- $a Y2
sSiteURL = value; 5/QRL\
} cE iu)2*e
SI_iI71
v_S4hz6w\
public String getSFilePath() zKFp5H1!%+
{ fZKt%m
return sFilePath; kGkA:g:
} Y:ldR
`imWc"'Ej
0GDvwy D1
public void setSFilePath(String value) muW!xY
{ T<-=nX
sFilePath = value; XCsiEKZ_i
} PS S?|Vk
'O6]0l
Gq#~vr
public String getSFileName() !TAp+b
{ as+GbstN
return sFileName; $3X-rjQtW
} O|cu.u|
%~NH0oFO
ZAuWx@}
public void setSFileName(String value) l$*=<tV
{ Q{QYBh&
sFileName = value; INSkgOo
} }%TSGC4{
OndhLLz
`N/RHb%
public int getNSplitter() 6+K_Z\
{ ]=73-ywn]
return nSplitter; d {2
} ~e@>zoM'^
@OV-KT[>
k;dXOn
public void setNSplitter(int nCount) z5Qs@dG
{ XA_FOw!cX
nSplitter = nCount; +~nzii3
} _U|7'^|
} Xj+q~4{|vt
wyxGe<1
:`vP}I ^
/* 6qo^2
**Utility.java >cL{Ya}Rz
*/ DZ ^1s~
package NetFox; s]27l3)B
HjWq[[Nz
=wi*Nd7L
public class Utility { *oI*-C
bVr*h2p
Z<b"`ty.
public Utility() Q}A=jew
{ qu6DQ@ ~YC
$trAC@3O@
r!N]$lB
} w-N1.^
@LD6:gy
//线程睡眠 [LM^),J?
public static void sleep(int nSecond) Fs/?
{ IxDWJ#k
try{ zGcqzYbuA
Thread.sleep(nSecond); (3,.3)%`
} 24\gbv<
catch(Exception e) [IM%b~j(^
{ &217l2X /
e.printStackTrace (); u3tZ[Y2 c
} (9fdljl],:
} a?cn9i)#
5iFV;W
//日志 VFD%h }
public static void log(String sMsg) MN;/*t
{ cJ}QXuuUv
System.err.println(sMsg); oholt/gb+0
} 1@sM1WMX
J_#R 87
0_<Nc/(P
public static void log(int sMsg) @u4=e4eF`
{ ? S=W&
System.err.println(sMsg); S9Y[4*//
} nX%AeDBAT
} =)<3pGO
#'o7x'n^
msTB'0
/* ]Nk!4"
**TestMethod.java s'a=_cN
*/ ;\)=f6N
package NetFox; 3-wD^4)O,
hY\{|
p_terD:
public class TestMethod { dXu{p
CVKnTEs
u"VS* hSH
public TestMethod() K!8zwb=fq
{ ///xx/weblogic60b2_win.exe Aa(<L$e!`
try{ CUmH,`hu
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +QqH}= M
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Zy]s`aa
SiteFileFetch fileFetch = new SiteFileFetch(bean); z)L}ECZh9
fileFetch.start(); {/M\Q@j
} ~5#)N{GbY
catch(Exception e){e.printStackTrace ();} ?s{C//
p%RUHN3G[
oFg'wAO.
} }N3`gCy9eN
XdIah<F2
JAb$M{t
public static void main(String[] args) >2-F2E,
{ Z^6#4Q]YC
new TestMethod(); CUhV$A#oo
} *=nO
} 2*[Un(
点击下载更多相关资料