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)); VWv0\:,G
} }$1;<
for(int i=0;i<nEndPos.length-1;i++) (O2HB-<rY
{ [BBKj)IK
nEndPos = nStartPos[i+1]; YoJ'=z,e
} BfT,
nEndPos[nEndPos.length-1] = nFileLength; q4iD59yd)S
} tJPRR_nZv
} #L0I+ K,K\
L"I] mQvd
B7MW" y
//启动子线程 ;x^,t@ xge
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wWU_?Dr_~
for(int i=0;i<nStartPos.length;i++) X);Zm7
{ IJY5wP1"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zD;] sk4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q;O)>K
nStartPos,nEndPos,i); AsLjU#jn
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `;CU[Ps?]
fileSplitterFetch.start(); \{zAX~k6
} \_AEuz3 F
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }~r6>7I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); BQ&q<6Tk
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c dbSv=r
nEndPos = " + nFileLength); ~hslLUE
// fileSplitterFetch[nPos.length-1].start(); N"RYM~c7
.Pes{uHg
psX%.95Y
//等待子线程结束 P`dHR;Y0
//int count = 0; 4F,Ql"ae(
//是否结束while循环 mv*T=N8fC
boolean breakWhile = false; 7EP|X.
G+ v, Hi1
a@y5JxFAy
while(!bStop) ^Lmc%y
{ zk'K.! `^
write_nPos(); <yI,cM<c
Utility.sleep(500); pJIE@Q|hi
breakWhile = true; `m3QT3B
g~c|~u(W
eSX[J6
for(int i=0;i<nStartPos.length;i++) O| J`~Lk
{ #;LMtDaL
if(!fileSplitterFetch.bDownOver) 8$v zpu
{ k5t^s
breakWhile = false; +lgF/y6
break; ?QSx8d
} L;M^>{>
} afF+*\xXN
if(breakWhile) Q A)9
break; 8| e$
|\%F(d330
D<bU~Gd,P
//count++; 0L0Jc,(F+
//if(count>4) ;eW'}&|LV
// siteStop(); )'!ml
} K@jSr*\'
}kCn@
|Sr\jUIWn
System.err.println("文件下载结束！"); m c\ C
} Z?(4%U5z
catch(Exception e){e.printStackTrace ();} !jAWNK6
} S@c\|
'EL ||
7.$]f71z
//获得文件长度 VPM|Rj:d
public long getFileSize() ]D{c4)\7C|
{ a*6wSAA )
int nFileLength = -1; Kunle~Ro
try{ niYz9YX
URL url = new URL(siteInfoBean.getSSiteURL()); }2Cd1RnS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W1?!iE~tO
httpConnection.setRequestProperty("User-Agent","NetFox"); U6juS/
Kd/[Bs%
:'d76pM-
int responseCode=httpConnection.getResponseCode(); Mu'^OX82
if(responseCode>=400) Bw3F7W~l
{ V;iL[
processErrorCode(responseCode); qSEB}1
return -2; //-2 represent access is error O1?B{F/ e
} [|a( y6Q
wTTTrk
ezcS[r
String sHeader; [i(Cl}
#Rin*HL##
S9G8aea/
for(int i=1;;i++) 0W~.WkD
{ 0rku4T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); e1%rVQ(v
//Utility.log(in.readLine()); ;'Z,[a
sHeader=httpConnection.getHeaderFieldKey(i); ?trt4Tbe/
if(sHeader!=null) m,kvEQ3
{ @5dBb+0J
if(sHeader.equals("Content-Length")) A1=$kzw{UH
{ .wt>.mUH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &j wnM
break; CU7iva
} Y`[HjS,
} pE YrmC
else T^-H_|/M
break; H8=vQy
} qU /Wg
} hz>yv@1
catch(IOException e){e.printStackTrace ();} 0N} wD-
catch(Exception e){e.printStackTrace ();} Cx1Sh#9
M7cI$=G
?L~=Z\H
Utility.log(nFileLength); 2C 8L\
S3JygN*
+2_6C;_DX
return nFileLength; D=pI'5&
} iA{chQBr
2kmna/Qa6
.-1{,o/&Q
//保存下载信息（文件指针位置） 3<1HqU
private void write_nPos() G3^n_]Jb
{ NiJ?no
try{ 6r-<XNv)0
output = new DataOutputStream(new FileOutputStream(tmpFile)); F6neG~Y
output.writeInt(nStartPos.length); %lqG*dRx0
for(int i=0;i<nStartPos.length;i++) 4)>\rqF+v
{ zWR*g/i
// output.writeLong(nPos); VHXR)}
output.writeLong(fileSplitterFetch.nStartPos); "351s3ff
output.writeLong(fileSplitterFetch.nEndPos); q5K/+N^2?
} `- uZv
output.close(); #D*J5k>2
} e[VJ0 A=
catch(IOException e){e.printStackTrace ();} L^ jC& dF
catch(Exception e){e.printStackTrace ();} {u[K ^G
} /EAQ.vxI
4 *2>R8SX~
b3HTCO-,fC
//读取保存的下载信息（文件指针位置） %~v76;H<
private void read_nPos() Ul~}@^m]4}
{ W2o8Fu
try{ "lnk
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ] !*
int nCount = input.readInt(); Pt)}HF|u
nStartPos = new long[nCount]; 1_E3DXe
nEndPos = new long[nCount]; snk{u/0Xm
for(int i=0;i<nStartPos.length;i++) %?{2uMfq-f
{ YI(OrR;V
nStartPos = input.readLong(); |(8Hk@\CT>
nEndPos = input.readLong(); BKlc{=
} 0o'ML""j
input.close(); $!3t$-TSD
} EpS8,[w
catch(IOException e){e.printStackTrace ();} =rtA{g$)+
catch(Exception e){e.printStackTrace ();} +H^V},dBp!
} X72X:"
M&\?)yG
j!8+|eAkk
private void processErrorCode(int nErrorCode) s$y#Ufz
{ Cot\i\]jv
System.err.println("Error Code : " + nErrorCode); PHL@1K{)
} J,M5<s[Xqt
IF?B`TmZ
aiX;D/t?
//停止文件下载 r#w_=h)
public void siteStop() Xq)%w#l5?
{ *L8HC8IbH
bStop = true; u#k6v\/
for(int i=0;i<nStartPos.length;i++) GpQF* x
fileSplitterFetch.splitterStop(); &-)Y[#\J
8}E(UsTa
U$JIF/MO_
} %[CM;|?B4
} *t*&Q /W
//负责部分文件的抓取 "^e?E:( 3
**FileSplitterFetch.java "}aM*(l+\
*/ B]}V$*$\?
package NetFox; Z!l!3(<G.f
4W-+k
EuA<{%i
import java.io.*; `-YSFQ~O,
import java.net.*; /g7?,/vnZ
4'[ V'c\
BiCa "
public class FileSplitterFetch extends Thread { #]/T9:
|VEAzY|[#
? Z fhz
String sURL; //File URL * CGdfdxW
long nStartPos; //File Snippet Start Position ]c=1-Rl
long nEndPos; //File Snippet End Position D ;I;,Z
int nThreadID; //Thread's ID 17 iq
boolean bDownOver = false; //Downing is over ~*]`XL.-
boolean bStop = false; //Stop identical z(68^-V=:
FileAccessI fileAccessI = null; //File Access interface xyWdzc](p
'yjH~F.
GQBN-Qv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]lYEJ`
{ 5kNs@FP
this.sURL = sURL; BtApl)q#
this.nStartPos = nStart; Z*3}L
this.nEndPos = nEnd; ?^5*[H
nThreadID = id; ~y^lNgujO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &bK$!8Z
} JLn<,Gn)<\
fsuvg jlE
^{bEq\5&
public void run() *uM*)6O 3
{ VjMuU"++@
while(nStartPos < nEndPos && !bStop) PdBhX
{ B;_3IHMO
Mwk_SCy
QLg9aG|
try{ ^ w1R"qE"m
URL url = new URL(sURL); Pk_{{Z(1o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3mz>Y*^?0
httpConnection.setRequestProperty("User-Agent","NetFox"); 'PbA/MN
String sProperty = "bytes="+nStartPos+"-"; :[03upyS
httpConnection.setRequestProperty("RANGE",sProperty); Rx-i.EtZ
Utility.log(sProperty); ~riw7"
f`rz)C03
qEz'l'%(
InputStream input = httpConnection.getInputStream(); 4=:eGlU93U
//logResponseHead(httpConnection); dig76D_[e
^uzVz1%mM
?\r3 _
byte[] b = new byte[1024]; 3s`3}DKK
int nRead; ob #XKL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k<qH<<r*
{ ^u,x~nPXg
nStartPos += fileAccessI.write(b,0,nRead); Or>[_3
//if(nThreadID == 1) "ukbqdKD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E1_4\S*z
} iK:]Q8b
CU_06A|}
.x%SbG<k{
Utility.log("Thread " + nThreadID + " is over!"); ]Jqe)o
bDownOver = true; Z.JTq~`I
//nPos = fileAccessI.write (b,0,nRead); lsi8?91
} .#|pje^
catch(Exception e){e.printStackTrace ();} k#[s)Ja?s
} JY16|ia
} `_)dEu
!6C d.fpWL
:g";p.~=
//打印回应的头信息 rgY~8PY"
public void logResponseHead(HttpURLConnection con) ~]W8NaQB(
{ 6B{Awm@v}X
for(int i=1;;i++) $ 1ZY Vw
{ $n"Llw&)
String header=con.getHeaderFieldKey(i); CG;D(AWR;
if(header!=null) eGil`:JY"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h@d m:=ul
Utility.log(header+" : "+con.getHeaderField(header)); a=dN.OB}F7
else |?kH]Trr
break; 8 Hn{CJ~'
} u'p J9>sC
} -C+vmY*@
6wgOmyJx
U_No/$ b
public void splitterStop() !TFVBK
{ kn\>ZgU
bStop = true; b'YbHUyu
} x7?{*w&r
sh1()vT
x?IT#ty
} tDo0Q/`
icmDPq
xjN~Y D:
/* /rW{rf^
**FileAccess.java jo~Pr
*//文件访问(定位，写) F`u~Jx8.*
package NetFox; %`'VXR?`h=
import java.io.*; _f`m/l
:-)[B^0
zBbTj IFQ
public class FileAccessI implements Serializable{ ZE^de(Fm
rxARJso
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~CA+'e%~~
RandomAccessFile oSavedFile; K^bn4Nr
long nPos; k$UBZ,=iC
KB5{l%>
>@"j9
public FileAccessI() throws IOException ect?9S[!y
{ <_![~n$H
this("",0); EB#z\
} =%L^!//c
L*z;-,
`4CRpz
public FileAccessI(String sName,long nPos) throws IOException <Yc:,CU
{ G\Me%{b#
oSavedFile = new RandomAccessFile(sName,"rw"); 1 .M?Hp9i
this.nPos = nPos; nTAsy0p]
oSavedFile.seek(nPos); pqe**`z@y
} pGIeW}2'9
,>$#e1!J
II91Ia
public synchronized int write(byte[] b,int nStart,int nLen) ,J|};s+
{ HZT;7<
int n = -1; {x8`gP\H
try{ +K?h]v]%
oSavedFile.write(b,nStart,nLen); F!xK#~e
n = nLen; A-W7!0
} <R2
catch(IOException e) ^6*? a9jO>
{ o$-Phl
e.printStackTrace (); +FiV!nRkZ
} f_7p.H6\
[Ue>KG62=
%Y@3)
return n; ,w6?} N
} ^{s)`j'I*
Pc3u`QL?
_VlNZ/V
} i`Tne3)
rLwc=(|
a-3~HH
/* BXdT;b"J(
**SiteInfoBean.java ;[xDc>&("Q
*/ ql#K72s
package NetFox; "CaVT7L
v zn/waw
+|.#<]GA
public class SiteInfoBean { `drvu?F
x!< C0N>?z
M;(lc?Rv
private String sSiteURL; //Site's URL eN$~@'w
private String sFilePath; //Saved File's Path Cxh9rUe.
private String sFileName; //Saved File's Name eE&F1|8
private int nSplitter; //Count of Splited Downloading File j.z#fU
yR`-rJb V
<W?,n%
public SiteInfoBean() r[gV`khka
{//nSplitter的缺省值为5 rh!41
//default value of nSplitter is 5 d1,azM
this("","","",5); G67BQG\av
} -B_dE-l,
u4S3NLG)
%:??QD*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) sK\?i3<?
{ $]Q_x?
sSiteURL= sURL; +|}~6`
sFilePath = sPath; @1>83-p"X
sFileName = sName; }{lOsZA
this.nSplitter = nSpiltter; 9Dpmp|
J@Li*Ypo
D^A_0@
} F;zmq%rK
l"cYW9
89L-k%R
public String getSSiteURL() ^)SvH
{ pG" 4qw
return sSiteURL; # mzJ^V-
} nBNZ@nD
J|ILG
N+r~\[N\9
public void setSSiteURL(String value) -F*j`
{ "aP/214Ul
sSiteURL = value; k<:!^_3H
} MM97$
-<|Ebh d3
I($u L@$
public String getSFilePath() ue`F|
{ M~@\x]p >
return sFilePath; Db2G)63
} >_5D`^
P[Qr[74)
u^{Q|o:=x
public void setSFilePath(String value) LIR2B"3F
{ xd>2TW l#
sFilePath = value; HkQ2G}<
} -5Ccuk>6
08'JT{iid
NoPM!.RU{
public String getSFileName() iG<|3I
{ Jb0]!*tV
return sFileName; *EotYT
} >s1HQSe66
V-jo2+Y5=
w("jyvV[C
public void setSFileName(String value) {t9U]hX%A[
{ FMR0?\jnT
sFileName = value; oVLz7Y[JE
} MY0Wr%@#0
MM^tk{2?.
<1hwXo
public int getNSplitter() cW MZw|t
{ a5&wS@) ;
return nSplitter; SBYRN##n_
} [7$<sN<'
z9VQsC'K
YpuA,r;"
public void setNSplitter(int nCount) eNXpRvY
{ ma-|L3 #
nSplitter = nCount; >(\[$
} Tvk=NJ
} of(Nq@
l ='lV]
'dBzv>ngD
/* |=7%Edkd
**Utility.java _Jx?m
*/ EkJo.'0@
package NetFox; P~?u2,.E[
oE5+
NeNKOW#X
public class Utility { a8dR.
Jq.26I=
:S,#*rPKBK
public Utility() LxMOs Nv
{ vnIxI a
!N!M NsyDz
mTcLocx
} OY?uqP}c
CNP?i(Rk
//线程睡眠 J_`.w
public static void sleep(int nSecond) J\2F%kBej?
{ bk5~t'
try{ !rrjA$P<v
Thread.sleep(nSecond); |QHWX^pO
} %d*}:295
catch(Exception e) /wIZ '
{ /oWB7l&
e.printStackTrace (); ti'OjoJL
} c-gaK\u}j}
} Wlt shZo
F=#zy#@.
//日志 G|H\(3hHLZ
public static void log(String sMsg) Q}I.UG_
{ 4 9#I
System.err.println(sMsg); }LE.kd&
} !M}&dW2
t6~|T_]
))eR
public static void log(int sMsg) LZ^sc
{ eYS
System.err.println(sMsg); 5*ABw6'6
} |Z!C`G[
} ]jM D'vg^b
pvcf_w`n
qf ]ax!bK
/* /@on=~
**TestMethod.java c?wFEADn
*/ <$ '#@jW
package NetFox; Xr':/Qjf
BhNwC[G?m
R[oKhU
public class TestMethod { t+66kBN
{K:/(\
Qa"R?dfr
public TestMethod() eeuAo&L&
{ ///xx/weblogic60b2_win.exe b/<4\f
try{ y*_g1q$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4?8GK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1=#`&f5f&
SiteFileFetch fileFetch = new SiteFileFetch(bean); ? BBDk
fileFetch.start(); JB**z00;
} K@W~
catch(Exception e){e.printStackTrace ();} !07$aQYcd
'0?5K0 2(
=g?r.;OO
} <o p !dS
7!Fu.Ps >
Qg1LT8
public static void main(String[] args) mnG\UK,k
{ @p}H@#/u\
new TestMethod(); {"s9A&
} cjH ~H8
} x4fLe5xv
点击下载更多相关资料