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)); OG2&=~hOz-
} wXUgxa
for(int i=0;i<nEndPos.length-1;i++) F!ra$5u
{ @i@f@.t
nEndPos = nStartPos[i+1]; 87:V-*8
} 3>buZ6vh
nEndPos[nEndPos.length-1] = nFileLength; Ct9*T`Gl
} j79$/ Ol
} C: a</Sl
t3;QF
Hp-vBoEk
//启动子线程 '8UhYwyr
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; to;cF6X
for(int i=0;i<nStartPos.length;i++) $3{I'r]
{ ,IQ%7*f;O_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), txemu*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %51HJB}C]
nStartPos,nEndPos,i); AR5)Uws
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <~35tOpv
fileSplitterFetch.start(); )r:gDd#/X
} ?F@X>zR2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OT}^dPQe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +&8'@v$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1Et{lrgh f
nEndPos = " + nFileLength); MF.$E?_R
// fileSplitterFetch[nPos.length-1].start(); \$D41_Wt|
;F\sMf{
>&uR=Yd
//等待子线程结束 yI_MYL[
//int count = 0; XQ$9E?|=
//是否结束while循环 <5sP%Fs)
boolean breakWhile = false; _}:#T8h
e^Glgaf
-Oc
while(!bStop) NUGiDJ+[
{ &3bhK5P
write_nPos(); _&/2-3]\B
Utility.sleep(500); 6eAJ>9@x
breakWhile = true; #=aTSw X
@!2vS@f
!yf7y/qY
for(int i=0;i<nStartPos.length;i++) ]ag^~8bG @
{ Z^ }4bR]
if(!fileSplitterFetch.bDownOver) QF9$SCmv
{ (j884bu
breakWhile = false; Qe1WT T]:I
break; PW GNUNc
} '' Pfs<!
} ?/^x)Nm
if(breakWhile) !vH={40]
break; ;@G5s+<l
&Vmx<w
=U+_;;F=
//count++; k2ZMDU
//if(count>4) { ^ @c96&
// siteStop(); ^F`\B'8MF
} O(YvE
s!\Gi5b
R)BH:wg"
System.err.println("文件下载结束！"); -{s9PZ3~_
} cK~VNzsz
catch(Exception e){e.printStackTrace ();} 3pI)
} 299uZz}Y
%n:ymc $}
pl5Q2zq%
//获得文件长度 @rt}z+JF
public long getFileSize() W,sPg\G 3
{ UWg+7RL
int nFileLength = -1; <%EjrjdvL+
try{ C+X-Cp
URL url = new URL(siteInfoBean.getSSiteURL()); 6eHw\$/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u^]Z{K_B
httpConnection.setRequestProperty("User-Agent","NetFox"); I=}pT50~9
Q[UYNQ0w
8PwPI%Pb
int responseCode=httpConnection.getResponseCode(); 2)47$eu
if(responseCode>=400) o&U/e\zy
{ Cy'! >
processErrorCode(responseCode); G.sf>.[
return -2; //-2 represent access is error 3IDX3cM9
} -q}I; cH
:dj=kuUTbu
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String sHeader; e? n8S
%][6TZ}
t[Ywp!y[
for(int i=1;;i++) *d$r`.9j
{ xmbFJUMH
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Xe>
//Utility.log(in.readLine()); H|/U0;s
sHeader=httpConnection.getHeaderFieldKey(i); _/)HAw?k
if(sHeader!=null) _V_GdQ
{ Jw)-6WJ!uO
if(sHeader.equals("Content-Length")) }@Ou]o
{ A<<Bm M.%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `]4bH,%~
break; i $;y
} 7=[/J*-m
} R?H[{AX
else =>,X)+O
break; NncII5z
} %6HJM| {H
} k9 NPC"
catch(IOException e){e.printStackTrace ();} V{yk
catch(Exception e){e.printStackTrace ();} Tl`HFZQ1
f4r)g2Zb[
mZ}C)&,m2
Utility.log(nFileLength); [V_\SQV0
+DA,|~k_
pQ yH`
return nFileLength; R1NwtnS
} Q9NKQuSu
-VhxnhS
@86?!0bt
//保存下载信息（文件指针位置） QPJz~;V2
private void write_nPos() g.d~`R@v
{ TxXX}6
try{ i :Sih"=
output = new DataOutputStream(new FileOutputStream(tmpFile)); El4SL'E@
output.writeInt(nStartPos.length); BhC>G2 ^7
for(int i=0;i<nStartPos.length;i++) !+Us)'L
{ e]@R'oM?#`
// output.writeLong(nPos); I2^Eo5'
output.writeLong(fileSplitterFetch.nStartPos); @bO/5"X,
output.writeLong(fileSplitterFetch.nEndPos); Y!w {,\3
} (|U|>@
output.close(); z<,rE
} KB6`OT^b{r
catch(IOException e){e.printStackTrace ();} _)=eE
catch(Exception e){e.printStackTrace ();} ,ou&WI yC
} w-?|6I}T
ua]?D2
ry!0~ir
//读取保存的下载信息（文件指针位置） zaMKwv}BR
private void read_nPos() o%.0@W
{ YH/3N(],
try{ VAet!H+]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); yy#4DYht
int nCount = input.readInt(); FCA]zR1
nStartPos = new long[nCount]; 2}jC%jR2
nEndPos = new long[nCount]; }Z3+z@L
for(int i=0;i<nStartPos.length;i++) *#g[ jl4
{ Z@ZSn0
nStartPos = input.readLong(); \:|"qk
nEndPos = input.readLong(); @w{"6xc%a
} o0\d`0-el
input.close(); 2V)qnMxAZJ
} "Iwd-#;$;
catch(IOException e){e.printStackTrace ();} ^U[yk'!Y
catch(Exception e){e.printStackTrace ();} ~fR-cXj"
} /XZ\Yy=
Xw |6 #^
L+J)
private void processErrorCode(int nErrorCode) cOo@UU P
{ ] R-<v&O
System.err.println("Error Code : " + nErrorCode); mqk tM6
} n06Jg+
B[B(=4EzMP
mdy+ >e<
//停止文件下载 6BIr{SY
public void siteStop() }hA h'*(
{ 9G=HG={
bStop = true; CWW|?
for(int i=0;i<nStartPos.length;i++) v!77dj 6I
fileSplitterFetch.splitterStop(); 85 <%L:EC
MMS#Ci=Lj
|+r5D4]e
} [&h%T;!Qii
} 1J @43>u{
//负责部分文件的抓取 :elTqw>pn
**FileSplitterFetch.java 7zEpuw
*/ Zq\Vq:MX
package NetFox; Q3|I.I e
z)0%gd|
$mLiEsJ
import java.io.*; I^itlQ
import java.net.*; BOf)27)
#) bqn|0l
fOkB|E]
public class FileSplitterFetch extends Thread { jO6yZt
\\i$zRi
/o]j
String sURL; //File URL vQhi2J'
long nStartPos; //File Snippet Start Position ruK,Z,3Q
long nEndPos; //File Snippet End Position T$r?LIa ,Q
int nThreadID; //Thread's ID qbu5aK}+
boolean bDownOver = false; //Downing is over &p6^
boolean bStop = false; //Stop identical +U= !svE
FileAccessI fileAccessI = null; //File Access interface RuuXDuu:VL
V07? sc<
1H]E:Bq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &RbT&
{ 'Bb@K[=s
this.sURL = sURL; /woC{J)4p
this.nStartPos = nStart; 2#g4R
this.nEndPos = nEnd; to"[r
nThreadID = id; F}dq~QCzw
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $mZpX:7/u8
} j3yz"-53e
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rN5;W
public void run() JwMFu5@
{ >$dkA\&p
while(nStartPos < nEndPos && !bStop) k:k!4
{ )'Yoii{dSU
IWD21lS
Fl;!'1
try{ -|x YT+?%
URL url = new URL(sURL); j~VHU89
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KuohUH+
httpConnection.setRequestProperty("User-Agent","NetFox"); .,7ZDO9{
String sProperty = "bytes="+nStartPos+"-"; tpP2dg9dF
httpConnection.setRequestProperty("RANGE",sProperty); [V_?`M
Utility.log(sProperty); JHIXTy__
"Ir.1FN
Mh;rhQ
InputStream input = httpConnection.getInputStream(); g1zX^^nd,V
//logResponseHead(httpConnection); "}'Sk(
Q]NGd 0J
H]JVv8
byte[] b = new byte[1024]; #Y'svn1H
int nRead; 2*1FW v
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) D|rcSa.M
{ <"rckPv_H
nStartPos += fileAccessI.write(b,0,nRead); &6}] v:
//if(nThreadID == 1) z~+gche>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Qpaan
} E+|r h-M7
vspub^;5\
8 y+Nl&"V
Utility.log("Thread " + nThreadID + " is over!"); }j /r
bDownOver = true; Q($aN-
//nPos = fileAccessI.write (b,0,nRead); 2lm{:tS
} baL-~`(T
catch(Exception e){e.printStackTrace ();} e+=IGYC
} Y^P'slY{%
} b/g"ws_
l5bd);Ltq
^vH3 -A;*
//打印回应的头信息 SuU %x2
public void logResponseHead(HttpURLConnection con) b$Ch2Qz0q
{ 6a\YD{D] _
for(int i=1;;i++) dxIt.h
{ `GD>3-
String header=con.getHeaderFieldKey(i); _$Hx:^p:
if(header!=null) KB^i=+xr
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |#D$9+
Utility.log(header+" : "+con.getHeaderField(header)); wBK%=7
else uRu)iBd D
break; M$Of.
} )-4xI4
} b+`mh
>4lT0~V/
_Z|3qQ
public void splitterStop() rJ UXA<:2
{ ]A2l%V_7
bStop = true; V*U*_Y
} :*wjC.Z
_hb@O2f
;uazQyo6
} t%f6P
%95'oW)lo
U'tfsf/V
/* 0 w#[?.
**FileAccess.java Sn lKPd
*//文件访问(定位，写) &R "Q
package NetFox; A+Xk=k5<
import java.io.*; #=hI}%n
@]0;aZ{3
<_tkd3t#W
public class FileAccessI implements Serializable{ 7~V,=WEe
dq{wFI)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 AqzPwO^
RandomAccessFile oSavedFile; }`,}e259
long nPos; !7O!)WJ
"""gV)Y
utvZ<zz`
public FileAccessI() throws IOException 2"~QI xY=
{ oT\u^WU
this("",0); -b4#/q+bb+
} LJ|2=lI+jb
e:~r_,K
iJrF$Xw
public FileAccessI(String sName,long nPos) throws IOException !L#>wlX)
{ 1*"t-+|
oSavedFile = new RandomAccessFile(sName,"rw"); oVLgHB\zL
this.nPos = nPos; :OVre*j
oSavedFile.seek(nPos); =a<};X
} &l=%*`On
M=hH:[6 &
>7VOytc
public synchronized int write(byte[] b,int nStart,int nLen) uWYI p\NN
{ hK,e<?N^
int n = -1; G Uf[Dz
try{ (1pxQ%yEA
oSavedFile.write(b,nStart,nLen); UtF8T6PKdW
n = nLen; 7X$[E*kd
} dT%$"sj5
catch(IOException e) DUk&`BSJ
{ LH4!QDK-
e.printStackTrace (); -o8H_MR
} wW~y?A"{2
q}PeXXH
H?~|Uj 6
return n; zw`T^N#
} c7[<X<yk
0Jh^((i*
1XAXokxj
} Gyak?.@R
:K ^T@F5n
=7JvS~s
/* s0 ZF+6f
**SiteInfoBean.java J2$L[d^
*/ *Op;].>E
package NetFox; >[=fbL@N<@
^ 2"r't
nVF?.c
public class SiteInfoBean { Dk!;s8}*c
+mQMzZZTZ
9y(75Bn9
private String sSiteURL; //Site's URL R&cOhUj22J
private String sFilePath; //Saved File's Path 37hs/=x
private String sFileName; //Saved File's Name R#ABda9
private int nSplitter; //Count of Splited Downloading File GHaOFLY
.a%D:4GYR
,Jy@n]x
public SiteInfoBean() +!'\}"q
{//nSplitter的缺省值为5 vps</f!
//default value of nSplitter is 5 v2e*mNK5
this("","","",5); =l_B58wrx
} )uvs%hK
[*<F
d%:B,bck
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2NHkK_B1P
{ M^c`j#NQ
sSiteURL= sURL; U{vt9t
sFilePath = sPath; g]IRv(gDh
sFileName = sName; la7VeFT
this.nSplitter = nSpiltter; RKu'WD?sdH
2sj[hI
I%]~]a
} jN\} l|;q
'u6T^YS
mXd,{b'
public String getSSiteURL() PuvC MD
{ Y40`~
return sSiteURL; &@tD/Jw3
} :a M ZJm
*f%uc
si:p98[w
public void setSSiteURL(String value) UEZnd8
{ p5|.E
sSiteURL = value; v=kQ/h
} -}u=tiNG
R?)M#^"W
Mu,}?%
public String getSFilePath() !_Z\K$Ns
{ l<5@a (
return sFilePath; `0.<
} Y}<w)b1e|
6w3z&5DY|
D00I!D16
public void setSFilePath(String value) !~+"TI}_%w
{ 'R&Y pR
sFilePath = value; X]^FHYjhS
} )-D{]>8
C`s
;B4x>
public String getSFileName() ldd|"[Ds
{ ]ZV.@%+
return sFileName; v6Vieo=
} P9Yee!*H
CH!>RRF
S$ u`)BG):
public void setSFileName(String value) Wpgp YcPS
{ HeV6=&#
sFileName = value; @>>8CU^~
} Y?ADM(j
+#%#QL
BE`{? -G
public int getNSplitter() [1+ o
{ F1m 1%
return nSplitter; :@mBSE/
} 0GEM3~~D.?
Q"o* \I
!*[Fw1-J
public void setNSplitter(int nCount) lD`@{A
{ tM&O<6Y
nSplitter = nCount; Ri[ v(Zf
} /y8=r"'G
} 7Cx*Ts$
!V<c:6"
\<cs:C\h7
/* 0\qLuF[)
**Utility.java >XTDN
*/ I},]Y~Y3
package NetFox; MHl ffj
MR=dQc
|p4D!M+$7
public class Utility { %y7&~me
]2:w?+T
UweXz.x7
public Utility() QCm93YZs6E
{ "!-
7T\LYDT
gu~JB
} rM?O2n
:6}Zo
//线程睡眠 Q9Tt3h2ga
public static void sleep(int nSecond) = aO1uC|6C
{ kn$2_I9
try{ x9QUo*MT
Thread.sleep(nSecond); y\a@'LFL
} t@#+vs@
catch(Exception e) 5 )A(q\
{ XZh1/b^DMN
e.printStackTrace (); w^{qut.
} 9i6z p'
} $-J0ou8~
rI'kGqU
//日志 ^bD)Tg5K
public static void log(String sMsg) *Z9Rl>
{ D)O2=aQ;]
System.err.println(sMsg); p`+=) n
} [8kufMY|
'P AIh*qA
!6`pq
public static void log(int sMsg) n]%T>\gw
{ 5L?_AUL
System.err.println(sMsg); `\p5!Iq Q
} c @U\d<{w
} W"{:|'/v
i1c z+}
Quq X4
/* i%FpPni
**TestMethod.java [Sj _=
*/ a)o-6
package NetFox; q0m>NA
. r?URC
e(z'uA{!
public class TestMethod { ]QJN` ;b0
w\K(kNd(
Wr j<}L|
public TestMethod() 5bj9S
{ ///xx/weblogic60b2_win.exe Zra P\?
try{ pu"m(9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3+<f7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r(ZMZ^
SiteFileFetch fileFetch = new SiteFileFetch(bean); kndN} Vq
fileFetch.start(); >D\jyd$wh&
} mXSs:FqE!
catch(Exception e){e.printStackTrace ();} 7hzd.
c,yjsxETW
J4) ?hS
} >h Rq
t}Q PPp y
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public static void main(String[] args) &6@#W]_
{ MnPk+eNJm
new TestMethod(); yq=rv$.s
} |34M.YjA
} 5/E7@h ,
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