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)); f*uD9l%/
} XwerQwO=
for(int i=0;i<nEndPos.length-1;i++) )U$]J*LI
{ Vy+UOV&v-
nEndPos = nStartPos[i+1]; zLeId83>
} (K"8kQLY
nEndPos[nEndPos.length-1] = nFileLength; =5zx]N1r
} 6X1_NbC
} ,sn/FT^; q
+[2X@J
rEWPVT
//启动子线程 OI0tgkG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; W5#5RK"uX
for(int i=0;i<nStartPos.length;i++) ga#Yd}G^~3
{ O7KR~d
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c"<bq}L7S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), N=?! ~n9Q-
nStartPos,nEndPos,i); fBZ\,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3aK/5)4|B
fileSplitterFetch.start(); BAUo`el5
} !uno!wUIYd
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `;'fCO!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [>pqf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", HJV8P2f8`
nEndPos = " + nFileLength); qrq9NPf
// fileSplitterFetch[nPos.length-1].start(); P2Or|_z
KR4vcI[4
G\HU%J
//等待子线程结束 r]0UF0#
//int count = 0; [u=DAk?8
//是否结束while循环 K9BoIHo
boolean breakWhile = false; TAXl73j_CY
~582'-=+
0xNlO9b/
while(!bStop) 'yq'J)
{ I,0]> kx
write_nPos(); &R'%OFi
Utility.sleep(500); TLkJZ4}?Q
breakWhile = true; /p&)bL
>Za66<:
qL\*rYe<
for(int i=0;i<nStartPos.length;i++) GA8cA)]zOD
{ Ul EP;
if(!fileSplitterFetch.bDownOver) k*;2QED
{ [H3~b=
breakWhile = false; Q I.*6-(
break; ,;_D~7L
} jE&Onzc
} -6()$cl}0
if(breakWhile) E?& x5?
break; bhFAt1h
rI[Lg0S
]:Q7Gys
//count++; }PR^Dj.
//if(count>4) K%p*:P
// siteStop(); /&+6nOP
} qM$~5uu
Nr#Y]9nA
HxVQeyOR
System.err.println("文件下载结束！"); })l+-H"
} yk5T"#'+
catch(Exception e){e.printStackTrace ();} }UzO_&Z#6
} <IF\;,.c
jZ'y_
<N{pMz
//获得文件长度 iZ`1Dzxgk
public long getFileSize() us.+nnd
{ ~YuRi#CTD:
int nFileLength = -1; |sw&sfH[FD
try{ AR}M*sSh
URL url = new URL(siteInfoBean.getSSiteURL()); `B`/8Cvg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :*2+t-
httpConnection.setRequestProperty("User-Agent","NetFox"); F7(~v2|
lRn6Zh
v!;E1
int responseCode=httpConnection.getResponseCode(); Yg;g!~
if(responseCode>=400) %;.|?gR
{ %5_eos&<^)
processErrorCode(responseCode); ,u}n!quA
return -2; //-2 represent access is error ==psPyLF@
} ))n7.pB9/
o(W|BD!
@"~Mglgw
String sHeader; %qzpt{'?<
7eh|5e$@
mf26AIlkQ
for(int i=1;;i++) 5k`[a93T
{ F_SkS?dB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !Xwp;P=
//Utility.log(in.readLine()); @"}dbW<DV
sHeader=httpConnection.getHeaderFieldKey(i); I +,D,Vg
if(sHeader!=null) `p&ko$i2
{ }lgqRg)F9[
if(sHeader.equals("Content-Length")) 6(4o}Sv
{ `>fN?He
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JlsRP
break; kWfNgu$xK
} eiZv|?^0
} auP:r
else i3.8m=>
break; bOCdf"!g
} dXh@E7
} iSxxy1R
catch(IOException e){e.printStackTrace ();} 'JEZ;9}
catch(Exception e){e.printStackTrace ();} 4\q7.X+^
_%s_w)
B{ NKDkDH
Utility.log(nFileLength); ,q#^_/?
]xfAdBi
r*/Pyh
return nFileLength; !oU$(,#9
} !MB%
&7 }!U
OwP9=9};
//保存下载信息（文件指针位置） vd-`?/,||
private void write_nPos() k@5,6s:
{ I}Z[F,}*J
try{ -A9 !Y{Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y*``C):K%
output.writeInt(nStartPos.length); wLD/#Hfi7
for(int i=0;i<nStartPos.length;i++) ~(B\X?v
{ p5C sw5
// output.writeLong(nPos); Sv-}w$
output.writeLong(fileSplitterFetch.nStartPos); w\Q3h`.
output.writeLong(fileSplitterFetch.nEndPos); !^ 6x64r
} qH6DZ|
output.close(); tc@U_>{
} q*A2>0O
catch(IOException e){e.printStackTrace ();} Q8M&nf
catch(Exception e){e.printStackTrace ();} nJ4h9`[>V
} 4j!MjlG$
.i/]1X*;r^
(0W%YZ!&
//读取保存的下载信息（文件指针位置） i^uC4S~
private void read_nPos() zUqiz
{ JRA.,tQc
try{ _]tR1T5e
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .jr1<LE
int nCount = input.readInt(); >qx~m>2|8]
nStartPos = new long[nCount]; g\ @nA4
nEndPos = new long[nCount]; kTex>1W;
for(int i=0;i<nStartPos.length;i++) *6Rl[eXS
{ ~u8}s4
nStartPos = input.readLong(); aQN`C{nY
nEndPos = input.readLong(); hzPx8sO
} 5vYh~|
input.close(); "h7-nwm
} %>i7A?L
catch(IOException e){e.printStackTrace ();} mo#4jtCE
catch(Exception e){e.printStackTrace ();} e=Kv[R'(M
} c6s(f
5S$HDO&
t2OXm
private void processErrorCode(int nErrorCode) Rv q_Zsm
{ N) {
System.err.println("Error Code : " + nErrorCode); ;lX:EU
} {<~XwJ.
$Miii`VS9
6FSw_[)
//停止文件下载 wXZ.D}d
public void siteStop() vG\]xM'u
{ w}NgFrL
bStop = true; 30>TxL=&
for(int i=0;i<nStartPos.length;i++) Eg-b5Z);
fileSplitterFetch.splitterStop(); <4{@g]0RV
'[Oi_gE.
AXPUJ?V
} u{H,i(mx?
} 7L;yN..0
//负责部分文件的抓取 e^&YQl
**FileSplitterFetch.java um#;S;
*/ (fh:q2E#
package NetFox; NFLmM
B[4y(Im
$'9r=#EH
import java.io.*; Z mi<Z
import java.net.*; {yt]7^
f`A
r-N2*uYtu
public class FileSplitterFetch extends Thread { lu(G3T8
(P`{0^O"}
]N=C%#ki!
String sURL; //File URL .2xypL8(
long nStartPos; //File Snippet Start Position Oku4EJFJ
long nEndPos; //File Snippet End Position m3_e]v3{o
int nThreadID; //Thread's ID P603P
boolean bDownOver = false; //Downing is over >+vWtO2
boolean bStop = false; //Stop identical :1Fm~'
FileAccessI fileAccessI = null; //File Access interface .[1A
Q=PaTh
7U.g4x|<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N%r}0
{ 7=QV^G
this.sURL = sURL; D<++6HN&#
this.nStartPos = nStart; Mh+'f 93
this.nEndPos = nEnd; >j`*-(`2fa
nThreadID = id; 0^E!P>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :WA o{|&
} qZ\zsOnp
"mPa>`?
Go`omh b
public void run() z(\H.P#
{ oSa FmP
while(nStartPos < nEndPos && !bStop) t_]UseP$RF
{ CdaB.xk
/mD KQ<
(sqS(xIY
try{ )&dhE^ O
URL url = new URL(sURL); d}l^yln
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !+hX$_RT
httpConnection.setRequestProperty("User-Agent","NetFox"); VpVw:Rh>
String sProperty = "bytes="+nStartPos+"-"; ['R=@.
httpConnection.setRequestProperty("RANGE",sProperty); 3lL:vD5(
Utility.log(sProperty); M0]l!x#7
"apv)xdW
KG3*~G
InputStream input = httpConnection.getInputStream(); TJ;v}HSo
//logResponseHead(httpConnection); =dA T^e##
}7.q[ ^oF
EL}v>sC
byte[] b = new byte[1024]; Tl%4L% bE
int nRead; *|E@81s#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [qZ4+xF,,
{ s}z,{Y$-t
nStartPos += fileAccessI.write(b,0,nRead); X!2|_
//if(nThreadID == 1) }SN'*w@E
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <}mT[;:"
} @tj0Ir v
+] 5a(/m.~
ZcWl{e4
Utility.log("Thread " + nThreadID + " is over!"); Y}?@Pm drz
bDownOver = true; E,6E-9
//nPos = fileAccessI.write (b,0,nRead); epG;=\f}m`
} R3@iN&
catch(Exception e){e.printStackTrace ();} =oh6;Ojt
} XdS<51 C
} ~IqT>
njq-iU
X4k/7EA
//打印回应的头信息 F_r eBPx
public void logResponseHead(HttpURLConnection con) /uyQ>Y*-\Y
{ ix#
for(int i=1;;i++) D$mrnm4d
{ l:|Fs=\
String header=con.getHeaderFieldKey(i); -{7N]q)}
if(header!=null) _:K}DU'6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =[jBOx&
Utility.log(header+" : "+con.getHeaderField(header)); o>*{5>#k'
else |1<Z3\+_/
break; 3+$O#>
} [`b{eLCFX]
} VuBp$H(U
mPD'"
MnS"M[y3
public void splitterStop() @'rO=(-b
{ % (.PRRI
bStop = true; 3PEs$m9e
} }GC{~ SZ4
aLq;a
\bsm#vY,
} ibAA:I,d
gU%GM
LtU+w*Gj
/* wS^-o
**FileAccess.java v6n(<0:
*//文件访问(定位，写) T*ic?!
package NetFox; Bf}_ Jw-=
import java.io.*; A+l"
s-ou;S3s
>mV""?r]
public class FileAccessI implements Serializable{ gJ7$G3&oZg
#RD%GLY
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;'Q{ ywr
RandomAccessFile oSavedFile; (j/O=$mJ
long nPos; p4Y9$(X
,-"]IR!,w
C;ye%&g>
public FileAccessI() throws IOException W9D)QIqbvW
{ lm\u(3_$
this("",0); 19vD(KC<
} Mzd}9x$'J
:W&\})
{h=Ai[|l4Q
public FileAccessI(String sName,long nPos) throws IOException pZjFpd|
{ [~o3S$C&7
oSavedFile = new RandomAccessFile(sName,"rw"); -+=8&Wa
this.nPos = nPos; Ygl!fC 4b
oSavedFile.seek(nPos); {HU48v"W
} gn%"dfm
: L>d]Hn
`otQ'e~+t
public synchronized int write(byte[] b,int nStart,int nLen) *k}d@j,*"
{ ~h/U ;Da
int n = -1; UGMdWq
try{ gkdjH8(2
oSavedFile.write(b,nStart,nLen); o(zg_!P
n = nLen; L}mhMxOTi
} x9e 9$ww}
catch(IOException e) vKC>t95
{ d0^2<
e.printStackTrace (); +x2xQ8#|~~
} P:vy
O+N-x8W{
t]ZSo-
return n; !jbjrzv9
} T,fz/5w
z|2liQrf+
]3C8
} V_pBM
Vh8uE
5-*]PAC
/* 9wC; m:
**SiteInfoBean.java i&$uG[&P
*/ #o RUH8
package NetFox; Sf8d|R@O
+\%zy=
xlLS`
public class SiteInfoBean { rBf?kDt6l
Ydx5kUJV<
;k8}D*?8
private String sSiteURL; //Site's URL MlZ`g,{
private String sFilePath; //Saved File's Path cOQy|v`KD,
private String sFileName; //Saved File's Name 9?8`"v
private int nSplitter; //Count of Splited Downloading File 3^Zi/r
?q P}=nJ
D|o@(V
public SiteInfoBean() %8Z,t+'
{//nSplitter的缺省值为5 qHCs{ u
//default value of nSplitter is 5 X3[!xMij
this("","","",5); )R4<* /C:w
} :m\KQ1sq
u_BSWhiW
hqPn~Tq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q*OKA5
{ UVK"%kW#(
sSiteURL= sURL; y#+o*(=fRE
sFilePath = sPath; <B`V
sFileName = sName; ShpnFuH
this.nSplitter = nSpiltter; lI 1lP 1
lNb\^b
={^#E?
} oK6lCGM5
|BW,pT
S2)S/ nf
public String getSSiteURL() _LNPB$P
{ 7;NV 1RV
return sSiteURL; 2#3R]zIO
} y`\Mhnj
.a*$WGb
1' m $_
public void setSSiteURL(String value) 9f\8oJQ
{ ^v-'=1ub?
sSiteURL = value; 919g5f`
} QGd- 9UEA]
p0K;m%
]aNnY?qW5
public String getSFilePath() <Z'hZ
{ lG9ARRy(=
return sFilePath; b U NYTF{
} rLxX^[Fp3
_GqE'VX
M-N2>i#
public void setSFilePath(String value) ozLJ#eOE9
{ fP58$pwu
sFilePath = value; (, "E9.
} $8k_M
keskD
NrcCUZ .:N
public String getSFileName() rzDJH:W{2
{ 4&e@>
return sFileName; ?LI9F7n
} p8l#=]\;
L?x?+HPY.
Z@!W?Ed
public void setSFileName(String value) I&8m5F?$`
{ I})t
sFileName = value; C4]%pi
} 2<Bv=B
@88i/ Z_
Ky#B'Bh}`g
public int getNSplitter() t[hocl/6
{ I!gj;a?R
return nSplitter; 9 w1ONw8v
} ?bAFYF0!I
gqRTv_;
T+RI8.#o
public void setNSplitter(int nCount) '*u;:[73
{ \_nmfTr!K
nSplitter = nCount; yPYJc
} ?4e6w
} #Hi]&)p_
@BUqQ9q:
AijTT%
/* $?AA"Nz
**Utility.java A(OfG&!
*/ uz3pc;0LPY
package NetFox; d~-p;i
*)1Vs'!-
Wxau]uix
public class Utility { ([b!$o<v
D"4&9"CU
\&&(ytL
public Utility() ) Zo_6%
{ 9,f<Nb(\
!]+Z%ed`%
5!jNL~M
} 6F.7Ws<
nDB 2>J
//线程睡眠 ;c Co+(
public static void sleep(int nSecond) aroVyUs3j
{ 9<h]OXv
try{ ds;cfj[
Thread.sleep(nSecond); nVn|$ "r
} UXPegK!
catch(Exception e) Wk#h,p3
{ E8_Le
e.printStackTrace (); tQ/ #t<4D
} kEhm'
} ct4 [b|
i4zV(
//日志 Qy5Os?9"
public static void log(String sMsg) D?yE$_3>c
{ <o!&Kk9
System.err.println(sMsg); _b_?9b-)D
} ``|RO[+2
dMs||&|&
{{*]bGko
public static void log(int sMsg) X";ZUp
{ !Nl.Vb
System.err.println(sMsg); M*|VLOo=v
} }"?nU4q;S
} Zxc7nLKF~
(s$u_aq77
? x"HX|n
/* !@<@QG-
**TestMethod.java [Z5[~gP3
*/ %aH$Tb%`hc
package NetFox; ] @)!:<+
MziZN^(
Np<&#s[dQ
public class TestMethod { ur<eew@8@i
H8$<HhuZM
S1^nC tSF
public TestMethod() /ggkb8<3
{ ///xx/weblogic60b2_win.exe Bug}^t{M
try{ YYE8/\+B.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z@,PZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); WVWS7N\
SiteFileFetch fileFetch = new SiteFileFetch(bean); n(1wdlEp
fileFetch.start(); 3p3WDL7
} {[,Wn:
catch(Exception e){e.printStackTrace ();} Q:kVCm/;
i&pJg1
6b]1d04hT
} ZEj!jWP2m
/MKNv'5&!%
_+\:OB[Y
public static void main(String[] args) ,9Z2cgXwJ
{ nx-1*
new TestMethod(); O~h94 B`
} (D>y6r>r
} XpgV09.EE
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