http断点续传简单实现（java)

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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)); gc<w nm|
} B3AWJ1o
for(int i=0;i<nEndPos.length-1;i++) {J&[JA\
{ ;?{[vLHDL
nEndPos = nStartPos[i+1]; !841/TRb
} /)+V(Jlu
nEndPos[nEndPos.length-1] = nFileLength; T`ofj7$:
} G 6r2 "
} j\hI, mc
d76nyQKK
a:v5(@8
//启动子线程 `jHbA#sO
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }}?,({T|n
for(int i=0;i<nStartPos.length;i++) zf4\V F
{ /Z~}dWI
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b((>?=hh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p<Oz"6_/~
nStartPos,nEndPos,i); ax)>rP,V
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q9G\T:^ury
fileSplitterFetch.start(); ?)-#\z=6G
} \&8 61A;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yg@8&;bP`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {s7 3(B"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W(#u^,$e[
nEndPos = " + nFileLength); c1Rn1M,2k
// fileSplitterFetch[nPos.length-1].start(); ^-^ii3G`
634OH*6
te[#FF3{
//等待子线程结束 m;4qs#qCg?
//int count = 0; rv?4S`Z,x$
//是否结束while循环 3< 'bi}{
boolean breakWhile = false; 1m~-q4D)V
W9D~:>^YP
<5 )F9.$
while(!bStop) {D$5M/$
{ /:Q
write_nPos(); <jAn~=Uq[,
Utility.sleep(500); 4 (c{%%
breakWhile = true; mu*RXLai
ljP<WD
B?nw([4m
for(int i=0;i<nStartPos.length;i++) Fp&tJ]=B.
{ UdOO+Z_K%
if(!fileSplitterFetch.bDownOver) >vPv4e7&3
{ _ ?o>i/
breakWhile = false; g)mjw
break; :<P3fW
} 2MU$OI0|
} \1ncr4
if(breakWhile) BjyV&1tRV!
break; $Ph#pM(
6 h%,%
Tlm::S
//count++; Fks #Y1rI
//if(count>4) V(5*Dn84
// siteStop(); }?)U`zF)7}
} p]eVby"
0FcG;i+
cj\?vX\V
System.err.println("文件下载结束！"); Ul<:Yt&nI
} Y|!m
catch(Exception e){e.printStackTrace ();} "wR1=&gk
} yz<$?Gblz
=5;tB
=E w<s5C@
//获得文件长度 Qv WvS9]
public long getFileSize() Q?2GwN
{ 8-"D.b4
int nFileLength = -1; ]~:WGo=_
try{ a@S{A5j
URL url = new URL(siteInfoBean.getSSiteURL()); 2,6~;R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0N87G}Xu
httpConnection.setRequestProperty("User-Agent","NetFox"); mUNAA[0 L
XI+GWNAmJ
Y#t9DhzFWo
int responseCode=httpConnection.getResponseCode(); tc0(G~.N
if(responseCode>=400) $@HW|Y
{ eg1Mdg\a
processErrorCode(responseCode); FnPn#Cv>*
return -2; //-2 represent access is error U4NH9-U'
} YuUJgt .1
wEF"'T
z"c,TlVN3
String sHeader; 4YSVy2x
5gSe=|we*p
YU`}T<;bg
for(int i=1;;i++) !l-Q.=yw
{ IP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,MjlA{0
//Utility.log(in.readLine()); c'INmc I|
sHeader=httpConnection.getHeaderFieldKey(i); MCAWn H
if(sHeader!=null) DkEf;P
{ 0|DyYu
if(sHeader.equals("Content-Length")) fcTg/EXn
{ " ?Ux\)*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ti^=aB
break; H0f]Swh0a
} tM|/OJ7
} t)5.m}
else BJt]k7ku+
break; S6<#] 6Z
} =h70!) Z5
} JM7FVB
catch(IOException e){e.printStackTrace ();} {DD #&B
catch(Exception e){e.printStackTrace ();} "%YVAaN
kX2Z@ w`
yAFt|<
Utility.log(nFileLength); ;\(LovUy6
*nK4XgD
lA`qB1x
return nFileLength; d`,z4_
} l{gR6U{e
Kk,u{EA
o)GesgxFa5
//保存下载信息（文件指针位置） #w@FBFr@
private void write_nPos() |\Q2L;4C
{ ]K'OH&
try{ 0RjFa;j
output = new DataOutputStream(new FileOutputStream(tmpFile)); o!lKP>
output.writeInt(nStartPos.length); &]tm'N25
for(int i=0;i<nStartPos.length;i++) 3+\Zom4
{ Z*b$&nM
// output.writeLong(nPos); $Xh5N3
output.writeLong(fileSplitterFetch.nStartPos); 0 ;].q*|#
output.writeLong(fileSplitterFetch.nEndPos); !"ir}Y%
} H.;2o(vD
output.close(); RBfzti6
} -Q/wW4dE=
catch(IOException e){e.printStackTrace ();} IE3GZk+a~
catch(Exception e){e.printStackTrace ();} Y4+]5;B8
} 1(pv3
rp4{lHw>C/
(f2r4Io|}
//读取保存的下载信息（文件指针位置） _F(Np\%_
private void read_nPos() 9C8 G(r
{ $o.;}
try{ r0@s3/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k8!:`jG
int nCount = input.readInt(); ,rjl|F* T
nStartPos = new long[nCount]; 4M!wm]n/%5
nEndPos = new long[nCount]; uzI-1@`
for(int i=0;i<nStartPos.length;i++) XgyLlp;,O
{ hE E1i
nStartPos = input.readLong(); Z^BZH/I?
nEndPos = input.readLong(); PC\p>6xT
} J7sH]
input.close(); e _(';Lk
} -Mf-8zw8G
catch(IOException e){e.printStackTrace ();} ^oYRBEIJH
catch(Exception e){e.printStackTrace ();} 0|]d^bo
} LqXVi80
3ZN\F
]9~Il#
private void processErrorCode(int nErrorCode) }ikN
{ Ct^=j@g
System.err.println("Error Code : " + nErrorCode); )H`V\H[0P
} x+TdTe;p
;n.h!wmJ}
G^cMY$?99
//停止文件下载 /;TtMQt
public void siteStop() m?gGFxo
{ YS@TQ?
bStop = true; 1JJ1!& >
for(int i=0;i<nStartPos.length;i++) $ce*W9`
fileSplitterFetch.splitterStop(); ;<GK{8
{>PEl;,-
B873UN
} PJ=|g7I
} c^cr_i
//负责部分文件的抓取 `Z#':0Z
**FileSplitterFetch.java k'*vG6!
*/ ri-D#F)}
package NetFox; ]rSg,Q>E
YNl".c
(.iwD&
import java.io.*; ;at1|E*
import java.net.*; obN8+ j
K}MlC}oIt
|3~]XN-
public class FileSplitterFetch extends Thread { Y DW^N]G
%iME[| u&
x3( ->?)D
String sURL; //File URL BR-wL3x b
long nStartPos; //File Snippet Start Position .S1MxZhbP
long nEndPos; //File Snippet End Position )*R';/zaI
int nThreadID; //Thread's ID MIyT9",Pl
boolean bDownOver = false; //Downing is over cW_l|
boolean bStop = false; //Stop identical q!+:zZu
FileAccessI fileAccessI = null; //File Access interface [$uKI,l
k7{|\w%
6nJQPa
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *YX5bpR?
{ #z70:-`.[M
this.sURL = sURL; u.G aMl4 (
this.nStartPos = nStart; FhPCFmmUT
this.nEndPos = nEnd; p-lFzNPc0
nThreadID = id; ]d~{8h!G
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '/9q7?[E!
} ;;m;f^]}
DSWmQQ
?Ok&,\F@E
public void run() rC]k'p2x
{ QhLgFu
while(nStartPos < nEndPos && !bStop) 19-V;F@;
{ m>F:dI
-/0aGqY
QC!SgV
try{ ,KD?kSIf
URL url = new URL(sURL); z;?j+ZsdH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fa\jVFIQ
httpConnection.setRequestProperty("User-Agent","NetFox"); ]T&d_~l
String sProperty = "bytes="+nStartPos+"-"; Ud2Tn*QmI
httpConnection.setRequestProperty("RANGE",sProperty); -j2y#aP
Utility.log(sProperty); Ml;` *;
?=^\kXc[
q9PjQ%
InputStream input = httpConnection.getInputStream(); l!KPgRw
//logResponseHead(httpConnection); (+cZP&o
NZ0?0*
_<DOA:'v
byte[] b = new byte[1024]; 6`G8UDK>F
int nRead; XN>bv|*q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4e;$+!dlV
{ %3|/t-US
nStartPos += fileAccessI.write(b,0,nRead); 4eG\>#5
//if(nThreadID == 1) LXsZk|IhM
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AaoS &q
} NQ;$V:s)
7-Oa34ba+
^ERdf2
Utility.log("Thread " + nThreadID + " is over!"); KZ%us6
bDownOver = true; (;^>G[
//nPos = fileAccessI.write (b,0,nRead); GQJ4d-w
} hQ!59
catch(Exception e){e.printStackTrace ();} j_~mP>el)
} i7v=o#
} '*&dP"
{o5^nd
I}5e{jBB
//打印回应的头信息 ](8F]J ,
public void logResponseHead(HttpURLConnection con) 1|!)*!hu
{ D`mr>-Y
for(int i=1;;i++) -meY[!"X
{ Iu~<Y(8^q#
String header=con.getHeaderFieldKey(i); r\FZ-gk}Q
if(header!=null) = &?&}pVF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); rly%+B `/
Utility.log(header+" : "+con.getHeaderField(header)); HRjbGc|[
else 3&5b!Y
break; I{WP:]"Yf
} D/ sYH0.V$
} l?rLadvc
|5:2?S2R
o1?-+P/
public void splitterStop() }p)Hw2
{ >SLmlK
bStop = true; p >ua{}!L
} -*~ @?
vfvp#
sf[|8}(
} 42A'`io[w]
Y'bz>@1(
f-|zh#L
/* j;V\~[I^u
**FileAccess.java sLJ]N0t
*//文件访问(定位，写) /V`SJ"
package NetFox; L6i|5 P
import java.io.*; :dRC$?f4
`Mbs6AJ
X%&7-PO
public class FileAccessI implements Serializable{ S w%6-
V=th-o3[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FE^/us7r
RandomAccessFile oSavedFile; GG<0k\RN
long nPos; U{bv|vF
IbL'Z
*| W*Mu
public FileAccessI() throws IOException +F8K%.Q_
{ kaiK1/W0;
this("",0); njZ vi}m~
} Yt,MXm\
^Go,HiB
W2fcY;HZ
public FileAccessI(String sName,long nPos) throws IOException XqUQ{^;aI
{ XksI.]tfj
oSavedFile = new RandomAccessFile(sName,"rw"); v_pe=LC{-e
this.nPos = nPos; n}e%c B
oSavedFile.seek(nPos); .boBb<
} _G@Zn[v
8 l)K3;q_
iM;Btv[|
public synchronized int write(byte[] b,int nStart,int nLen) 2p#d
{ i>[xN[U(
int n = -1; `w`N5 !
try{ 0*tnJB
oSavedFile.write(b,nStart,nLen); MN5}}@
n = nLen; k\;D;e{
} wbcip8<t
catch(IOException e) n'{jc6&|
{ x=L"qC9f/
e.printStackTrace (); '[%Pdd]! E
} 3`{;E{
DEhR\Z!
XOQ0(e6
return n; f(eXny@Y
} ';8 ,RTe
5S!j$_(
7-n HPDp'
} V9}\0joM
K@%T5M4j
km5gO|V>m
/* SqRM*Cf=
**SiteInfoBean.java 8v8-5N
*/ mwsBj)
package NetFox; "=C~IW
:AFU5mR4&
KnA BFH
public class SiteInfoBean { @NL<v-t
2)\MxvfOh
{ pQJ.QI
private String sSiteURL; //Site's URL Qt{V&Z7
private String sFilePath; //Saved File's Path `AvK8Wh<+
private String sFileName; //Saved File's Name 5 -|7I7(G$
private int nSplitter; //Count of Splited Downloading File "eOl(TSu/
^E\n^D-RV
}vOg9/[{
public SiteInfoBean() :@P6ibcX
{//nSplitter的缺省值为5 xoj,>[7 D
//default value of nSplitter is 5 QGV#AID3XW
this("","","",5); bV2a2#kj
} :E|Jqi\
"nfi:A1
,X:3w3nr^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xg^%8Ls^
{ SSla^,MHef
sSiteURL= sURL; 2dKt}o>
sFilePath = sPath; ^z{Xd|{"
sFileName = sName; R[m{"2|,Lc
this.nSplitter = nSpiltter; w6h83m 3
qN' 3{jiPL
7G;1n0m-T
} <oT1&C{
B6TE9IoSb8
5{+2#-
public String getSSiteURL() }:{ @nP
{ YT'V/8US
return sSiteURL; v?6*n>R
} KaOXqFT=
}Rh%bf7,
O/ItN5B ;
public void setSSiteURL(String value) "s]
{ XRQ1Uh6
sSiteURL = value; OgQ8yKfDB
} i%<NKE;v7m
AY<L8
*,:2O&P
public String getSFilePath() RFFbS{U*
{ 5[B)U">]
return sFilePath; b&4JHyleF
} OvwoU=u
)CE]s)6+2
!O`j
public void setSFilePath(String value) p<0=. ~
{ -EFdP]XO
sFilePath = value; #6YpV)
} Hf1b&8&:K
f_LXp$n
n/*" 2
public String getSFileName() qa@;S,lp
{ SDSP4W5
return sFileName; tq~f9EvC
} GhcH"D%-
PZ'|)
TJW8l[M
public void setSFileName(String value) *HHL a
{ [:(O`#
sFileName = value; K re*~ "
} eFf9T@
5izpQ'>
m*jE\+)=^
public int getNSplitter() ujBm"p_|
{ %uV,p!| )
return nSplitter; R1Q,m
} U,T#{
e:4,rfF1
hJ[keaO
public void setNSplitter(int nCount) }1V+8'D
{ JzCkVF$
nSplitter = nCount; KQ6][2-
} et/l7+/'
} <Z_\2 YWA
;@gI*i N"
cL.>e=x$
/* v^Fu/Y
**Utility.java o%z^@Cq
*/ RL]$"
package NetFox; Xg1TX_3Ml
dxZn| Y
tP2.D:( R
public class Utility { *&]8rm{
IDqUiN
WL'!M&h
public Utility() dQ_'8 )
{ NM),2%<
hSAI G
s[UV(::E
} hR2 R
qM 1ZCt
//线程睡眠 aL;zN%Tw
public static void sleep(int nSecond) 2sG1Hox
{ ,aP5)ZN-
try{ U Rq9:{
Thread.sleep(nSecond); 4, Vx3QFZ
} };"_Ku4#-
catch(Exception e) QZ7W:%r(4
{ Xa;wx3]t
e.printStackTrace (); H=WB6~8)
} ?5lO1(
} \SwqBw
HpUJ_pZ
//日志 o.|36#Fa
public static void log(String sMsg) o>d0R w4h
{ ?/hS1yD;
System.err.println(sMsg); MZA%ET,l,<
} Y:Lkh>S1Q
i Pl/I
zp'hA
public static void log(int sMsg) ?;5/"/i
{ Nknd8>Hy+
System.err.println(sMsg); ;O,&MR{;|n
} =)i^E9
} |FlB#
RhF<{U.
yU7XX+cB7
/* ND=JpVkvZ?
**TestMethod.java F &5iA\
*/ j1+I_
package NetFox; XS^du{ai
V8o, e
{IBbN05 ;
public class TestMethod { 5RO6YxQ
).u>%4=6
/Hm/%os
public TestMethod() /J!hKK^k
{ ///xx/weblogic60b2_win.exe &pz`gna
try{ e,#5I(E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); HD$`ZV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K~^o06 Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); LSXsq}
fileFetch.start(); 5OOXCtIKf
} ,?%Y*?v
catch(Exception e){e.printStackTrace ();} )ytP$,r![S
:AuKQ`c
P&Xy6@%[Z
} DSp~k)
:c )R6=v
UaQW<6+
public static void main(String[] args) e9S*^2;
{ \fUVWXv
new TestMethod(); B"*PBJuOA
} ga;t`5+d
} F60m]NUM)c
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