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)); {B,r
} ]v,>!~8r
for(int i=0;i<nEndPos.length-1;i++) }vspjplk^
{ %jnSJjcq
nEndPos = nStartPos[i+1]; csNB \
} [K4wd%+
nEndPos[nEndPos.length-1] = nFileLength; afNqK~
} L]ce13K
} w\QMA3
y1@*)| r
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//启动子线程 OPP^n-iPr
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $bd2TVNV:
for(int i=0;i<nStartPos.length;i++) [/iT D=O,
{ ~qj09
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @.SuHd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), oo{3-+ ?
nStartPos,nEndPos,i); ne(zGJd
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hEv}g
fileSplitterFetch.start(); o2vBY]Tj
} ^qP}/H[QT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 02F[4c~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); y+g01z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", QFYO_$1Y)
nEndPos = " + nFileLength); x{.+i'
// fileSplitterFetch[nPos.length-1].start(); H@%Y"iIUP
{} gr\
fu]mxGPc
//等待子线程结束 YN>k5\M_v
//int count = 0; MrGq{,6C
//是否结束while循环 >*FHJCe
boolean breakWhile = false; @;K-@*k3
s%c>Ge
U81--'@y
while(!bStop) 4Cn% h)w
{ MR{JMo=r
write_nPos(); GZ@`}7b}
Utility.sleep(500); ;ZVT[gi*
breakWhile = true; yv2N5IQ>{V
?cRGdLP'D
ejjL>'G/|%
for(int i=0;i<nStartPos.length;i++) 1#m'u5L
{ |1[3RnGS
if(!fileSplitterFetch.bDownOver) UBZ37P
{ ?!Bf# "TY
breakWhile = false; 6+s10?
break; wTw)GV4
} <*'%Xgm
} $wBF'|eU
if(breakWhile) *~>}*
break; Ub_!~tb}?
dr~6}S#
9z0G0QW[
//count++; ~aZy52H_#.
//if(count>4) ooW;s<6
// siteStop(); W3.(s~)o
} `z)q/;}fC
pdFa]
eGF+@)K1"
System.err.println("文件下载结束！"); >&g^ `
} ^KRe(
catch(Exception e){e.printStackTrace ();} _9<nM48+t
} V@C8HTg
k/;%{@G)
K\3N_ztu
//获得文件长度 )5NjwLs
public long getFileSize() tzn+ M0'
{ g,61'5\
int nFileLength = -1; iT2{3t
try{ 4[VW~x07
URL url = new URL(siteInfoBean.getSSiteURL()); *?v_AZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %/:0x:ns
httpConnection.setRequestProperty("User-Agent","NetFox"); Q 2mTu[tx
7XU$O$C
??u*qO:p
int responseCode=httpConnection.getResponseCode(); Wp2$L-T&$
if(responseCode>=400) L)qDtXd4
{ $]`rWSYtv`
processErrorCode(responseCode); yPXa
return -2; //-2 represent access is error c`E0sgp
} YQ7\99tj
wdo(K.m
99G'`NO
String sHeader; mY1Gm|
]o<&Q52|
|T) $E
for(int i=1;;i++) {IgLH`@
{ yRyUOTK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]I<w;.z
//Utility.log(in.readLine()); u"s@eN
sHeader=httpConnection.getHeaderFieldKey(i); `Hp=1a
if(sHeader!=null) gmW-#.
{ m*f"Y"B.1I
if(sHeader.equals("Content-Length")) =euMOs
{ o0}kRL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6a!b20IZh
break; V<&^zIJUR
} KKcajN
} \MU-D,@
else 9 7Ua,
break; #M5pQ&yZy
} >.o<}!FW
} W Yo>Md 8
catch(IOException e){e.printStackTrace ();} RE%25t|
catch(Exception e){e.printStackTrace ();} ;ZtN9l
fG_<HJS(~
4Wk`P]?^
Utility.log(nFileLength); #9e2+5s
/:.p{y
r"&uW!~0
return nFileLength; qvC2BQ
} #6F|}E
&y&pjo6v1
-SlAt$IJ
//保存下载信息（文件指针位置） o#\c:D*k
private void write_nPos() %u!)1oOIz
{ nIEIb.-
try{ 4L_AhX7
output = new DataOutputStream(new FileOutputStream(tmpFile)); n3" @E<rW
output.writeInt(nStartPos.length); ym;I(TC+
for(int i=0;i<nStartPos.length;i++) l0K_29^
{ #\l#f8(l
// output.writeLong(nPos); &\iMIJ-
output.writeLong(fileSplitterFetch.nStartPos); C1w6[f1+
output.writeLong(fileSplitterFetch.nEndPos); me YSW
} U_C[9Z'P
output.close(); O[j$n
} 7:'5q]9
catch(IOException e){e.printStackTrace ();} ,:6.Gi)|
catch(Exception e){e.printStackTrace ();} U:q4OtiP
} OD6dMql
9 Eqv^0u
cyH=LjgJf
//读取保存的下载信息（文件指针位置） c1M *w9o
private void read_nPos() ql I1<Jx
{ pqDlg
try{ f7?u`"C
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :/\KVz'fw}
int nCount = input.readInt(); DCSmEy`.
nStartPos = new long[nCount]; j*_>/gi
nEndPos = new long[nCount]; q"-+`;^7(-
for(int i=0;i<nStartPos.length;i++) U]PsL3:
{ kIJ=]wU|v
nStartPos = input.readLong(); WiqkC#N
nEndPos = input.readLong(); -?L3"rxAP
} #:E^($v
input.close(); q-r5zGI
} =6d'/D#J
catch(IOException e){e.printStackTrace ();} Zfc{}ius
catch(Exception e){e.printStackTrace ();} Q;k D Jo
} @g]>D
#SR )tU
l<UA0*t
private void processErrorCode(int nErrorCode) 4bq+(CI6
{ bo &QKK
System.err.println("Error Code : " + nErrorCode); [H=l#W@
} TUX:[1~Nf[
q22@ZRw
ekCt1^5Y
//停止文件下载 &\W5|*`x-
public void siteStop() /xb37,
{ gJg%3K~,
bStop = true; I|tn7|*-A[
for(int i=0;i<nStartPos.length;i++) S #C;"se
fileSplitterFetch.splitterStop(); 50^CILKo7
3^`.bm4 ^
p]Q(Z
} rU_FRk
} }w5`Oig[
//负责部分文件的抓取 yHs'E4V`$
**FileSplitterFetch.java 3A'9=h,lVK
*/ fiQ/ &]|5
package NetFox; (AT)w/
kPYQcOK8
97n,^t2F\
import java.io.*; <ahcE1h
import java.net.*; ZW ZKyJQ
qz }PTx
A&C?|M?M
public class FileSplitterFetch extends Thread { q)!G5j3
q]DE\*@
F>ps&h
String sURL; //File URL Qy\Koo
long nStartPos; //File Snippet Start Position e^h4cC\^
long nEndPos; //File Snippet End Position )%bY2 pk
int nThreadID; //Thread's ID 6BObV/S Jg
boolean bDownOver = false; //Downing is over l-q.VY2
boolean bStop = false; //Stop identical /jN&VpDG
FileAccessI fileAccessI = null; //File Access interface ka<rlh<h
}qN
t Z]b0T(e
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e$4l[&kH_
{ g.x]x#BC
this.sURL = sURL; eXCH*vZY
this.nStartPos = nStart; bdyIt)tK+
this.nEndPos = nEnd; @\Yu?_a
nThreadID = id; V3[>^ZCA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Jm3iYR+,
} q&@q/9kz
.xg, j{%(
Ew2ksZ>B]&
public void run() J72YZrc
{ _j?/O)M c
while(nStartPos < nEndPos && !bStop) }>?"bcJ
{ 6@J)kV
p} i5z_tS
|r/4 ({n
try{ \q:PU6q
URL url = new URL(sURL); }tPI#[cfK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bEl)/z*gy/
httpConnection.setRequestProperty("User-Agent","NetFox"); q6zKyOE
String sProperty = "bytes="+nStartPos+"-"; CDGN}Q2_
httpConnection.setRequestProperty("RANGE",sProperty); u =|A
Utility.log(sProperty); "kkZK=}Nv
qW t 9Tr
0 hS(9y40
InputStream input = httpConnection.getInputStream(); Jc,{n*
//logResponseHead(httpConnection); 8\rHSsP
pu5-=QN
S@eI3PkE
byte[] b = new byte[1024]; "hXB_73)V
int nRead; ]`}R,'P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3QD##Wr^
{ e]u3[ao
nStartPos += fileAccessI.write(b,0,nRead); QVQ?a&HYS
//if(nThreadID == 1) q/^&si
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 28d=-s=[
} aDE)Nf}
`"<tk1Kq"
ntEf-x<
Utility.log("Thread " + nThreadID + " is over!"); Oz7WtN
bDownOver = true; NTL`9b
//nPos = fileAccessI.write (b,0,nRead); (ZHEPN
} ?o.Q
catch(Exception e){e.printStackTrace ();} &#qy:
} ~U_,z)<`)c
} Qh@A7N/L
(f?&zQ!+
L\y>WR%s
//打印回应的头信息 2?nhkast#=
public void logResponseHead(HttpURLConnection con) ;c;PNihg
{ A+bU{oLr
for(int i=1;;i++) PH3#\ v.
{ 9|RR;k[
String header=con.getHeaderFieldKey(i); $.-\2;U
if(header!=null) 1U< g
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "+:~#&r
Utility.log(header+" : "+con.getHeaderField(header)); \hFIg3
else >$p|W~x
break; cQldBc
} l]v>PIh~N
} BjIKs~CT
KsBi<wY
RE}$(T=
public void splitterStop() *WpDavovyB
{ i& ybvTl
bStop = true; (lR9x6yf
} 1b-_![&]1
h?ZxS
x"QZ}28(t
} FZ^j|2.L*
V+2C!)f(
JJ$q*
/* 9Lv"|S`5W_
**FileAccess.java $C8nPl' 7
*//文件访问(定位，写) ]:vo"{*C
package NetFox; 'vUx4s
import java.io.*; ^z\*; f
%wuD4PRK
l gzA) (
public class FileAccessI implements Serializable{ p2:>m\
,wEcRN w
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JM-+p
RandomAccessFile oSavedFile; wA;Cj
long nPos; (5(TbyWwD
9akIu.H
{`M 'ruy.%
public FileAccessI() throws IOException !*@sX7H
{ xf]_@T;
this("",0); a@&P\"k
} 8Mf{6&F=
HRxA0y=
hbg:}R=B<
public FileAccessI(String sName,long nPos) throws IOException $D)Ajd;
{ MF["-GvP/
oSavedFile = new RandomAccessFile(sName,"rw"); oyeJ"E2
this.nPos = nPos; 4]18=?r>
oSavedFile.seek(nPos); Dw6mSsC/
} _wKaFf
3.?kxac
7; e$ sr
public synchronized int write(byte[] b,int nStart,int nLen) cq,0?2R`t
{ c$skLz
int n = -1; e=m=IVY#W
try{ 1$#{om9
oSavedFile.write(b,nStart,nLen); X|w[:[P
n = nLen; ,_(AiQK
} 8A ;)5!
catch(IOException e) nW*D
{ E'O[E=
e.printStackTrace (); zZax![Z
} t+?m<h6w;l
n$oHr
9Oe~e
return n; q/lQEfR
} ?' :v):J}
awic9uMH
BQ7p<{G
} H]x-s
%P2l@}?a
= olmBXn/
/* yxx'g+D*
**SiteInfoBean.java GF=rGn@,)`
*/ B3V;
package NetFox; HDY2<Hzc
EDf"1b{PX
0;V "64U
public class SiteInfoBean { ,p\:Z3{ZH
Adma~]T9
L" GQQ
private String sSiteURL; //Site's URL =W_Pph
private String sFilePath; //Saved File's Path d~F4
private String sFileName; //Saved File's Name .*(xkJI3
private int nSplitter; //Count of Splited Downloading File %HAforH
V6ICR{y<3
4fyds< f
public SiteInfoBean() 8*iIJ
{//nSplitter的缺省值为5 C3"5XR_Ov
//default value of nSplitter is 5 &xYO6_.
this("","","",5); #NZ#G~oeO
} ^.|P&f~
p?v.42R:z
_P{f+HxU
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y k{8O.g
{ 0lm7'H*~
sSiteURL= sURL; H-|%\9&{S
sFilePath = sPath; z?DI4O#Up
sFileName = sName; ^.HvuG},O
this.nSplitter = nSpiltter; :+qd>;yf#
7H l>UX,|
-$2a@K,i
} U7do,jCoa
hRwj-N%C
MoX~ZewWR
public String getSSiteURL() 9{KL^O?g
{ \~!!h.xR
return sSiteURL; TF1,7Qd
} ^tTASK
~EL3I
MOia]5
public void setSSiteURL(String value) rijavZS6
{ V*<`!w
sSiteURL = value; fFYfb4o
} y<5RV>"Vg
!ay:h Iv
p.^qB]%
public String getSFilePath() NZoNsNu*C.
{ m0Geq.
return sFilePath; }nUq=@ej
} SYE+A`a
Db`SNk=
dtT:,&
public void setSFilePath(String value) @y!oKF
{ Mm)yabP
sFilePath = value; !y\r.fm!A
} I?&/J4o:
8v}B-cS
[. Db56
public String getSFileName() {)jTq??
{ YT`,f*t
return sFileName; {Z,_/@}N
} .C*mDi)wZ
S6CI+W
-^aJ}[uaI
public void setSFileName(String value) [o"<DP6w
{ ?:$\ t?e^
sFileName = value; , UsY0YC
} Fd86P.Df
]?6Pt:N2
&.l^>#
public int getNSplitter() hGy[L3{
{ 1.tAl6]
return nSplitter; vvI23!H
} gHo sPY[
X`6"^ xme
7 'q *(v
public void setNSplitter(int nCount) QdrZi.qKH
{ g7"2}|qxo
nSplitter = nCount; (QTF+~)
} x:K~?c3
} :N^+!,i
zub"Ap3
b} 0G~oLP
/* ZuFcJ?8i
**Utility.java Vak\N)=u
*/ 8<)ZpB,7
package NetFox; hYht8?6}m
{vq| 0t\-
8c\\-{
public class Utility { M ui\E
O joa3
]t0St~qUL)
public Utility() J%u,qF}h
{ 'Qh1$X)R7a
F[v:&fle
BW:HKH.k
} )dd1B>ej]
2 EWXr+IU.
//线程睡眠 bp!Jjct
public static void sleep(int nSecond) O9C&1A|lA
{ %s! |,Cu
try{ H76iBJ66
Thread.sleep(nSecond); s IFE:/1,
} g<N;31:c\
catch(Exception e) ^)(-7H
{ B<Q)z5KK
e.printStackTrace (); 0NeIQr1N_
} *`q?`#1&&.
} ", p5}}/
Sv_Nb>
//日志 o"6 2~
public static void log(String sMsg) W,|+Dl
{ FUarI5#fwF
System.err.println(sMsg); kuI~lBWI
} `a%MD>R_Lg
?P}bl_
>J5C.hx
public static void log(int sMsg) T]JmnCX>:
{ q;}iW:r&Q
System.err.println(sMsg); \_ V*Cs
} _u+ 7>
} Mj{w/'
Pa6pq;4St
r'`7}@H*
/* * bd3^mP
**TestMethod.java $J^fpXO
*/ t/}NX[q
package NetFox; ^v`naA(
ftG3!}
9QaE)wt
public class TestMethod { ?ac4GA(
/O5&)%N
eP,bFc
public TestMethod() lYTQg~aPm
{ ///xx/weblogic60b2_win.exe o{6q>Jm
try{ \{}dn,?Fv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ruQt0q,W3%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pCDN9*0/
SiteFileFetch fileFetch = new SiteFileFetch(bean); gW,hI>
fileFetch.start(); lxm/*^
} R8cOb*D
catch(Exception e){e.printStackTrace ();} D<m0G]Ht*
X@"G1j >/
mU]VFPr5
} [ /YuI@C,@
\ )=WA!
xorafL
public static void main(String[] args) qm3H/cC9+
{ 4EHrd;|
new TestMethod(); >1(J
} u4_QLf@I
} 3 3|t5Ia
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