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)); zY].ZS=7
} .mxc~
for(int i=0;i<nEndPos.length-1;i++) %PPkT]~\
{ 2Ic)]6z R
nEndPos = nStartPos[i+1]; s,M]f,T
} 8/~@3-9EK
nEndPos[nEndPos.length-1] = nFileLength; eUD 5V
} m`4N1egCt
} KSUhB
af/0e}-
J@rBrKC
//启动子线程 }t1 q5@QU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D<[kbt5^7
for(int i=0;i<nStartPos.length;i++) eGWwPSIp
{ "M,Hm!j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =~q$k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `Y,Rk
nStartPos,nEndPos,i); NYR:dH]N~d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .{(gku>g(
fileSplitterFetch.start(); #=Whh 9-d
} >&T J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $4]4G=o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xg;F};}5$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;U?323Z
nEndPos = " + nFileLength); rgEN~e'
// fileSplitterFetch[nPos.length-1].start(); >B.KI}dE
uY3?(f#
nr&9\lG]G
//等待子线程结束 W^eQ}A+Z
//int count = 0; a24(9(yh
//是否结束while循环 +;q`A1
boolean breakWhile = false; /KlSI<T@
p;mV?B?oAQ
BNixp[Hc
while(!bStop) ^Jc|d,u;s
{ OSwum!hzN
write_nPos(); On,z#A
Utility.sleep(500); %)e&"mq!|
breakWhile = true; NkAu<> G _
LfvRH?<W
'Xasd3*Py
for(int i=0;i<nStartPos.length;i++) t;y@;?~
{ O44Fj)
if(!fileSplitterFetch.bDownOver) hKems3
{ 3X9
breakWhile = false; G(1_P1
break; V}h)e3X
} ) gxN'z
} :S+Bu*OyH
if(breakWhile) 0.B'Bvn=s2
break; 1W7ClT_cQ
"_\77cqpTh
[6nN]U~Y
//count++; \WZSY||C|_
//if(count>4) Zy>y7O(,
// siteStop(); M2A_T.F=H
} 98CS|NEe
c3O&sa V!
%KR2Vlh0
System.err.println("文件下载结束！"); NHhKEx0Gtu
} YIHGXi<"n
catch(Exception e){e.printStackTrace ();} F*y7 4j,
} I0_>ryA
Z_Y gV:jc
_ujhD
//获得文件长度 yz%o?%@
public long getFileSize() Yb'%J@T}
{ v/,,z+%-
int nFileLength = -1; "[CR5q9Pr
try{ gc W'
URL url = new URL(siteInfoBean.getSSiteURL()); YOY2K%o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >{"E~U
httpConnection.setRequestProperty("User-Agent","NetFox"); = @lM*
xBE}/F$45
SYgkYR
int responseCode=httpConnection.getResponseCode(); M4t:)!dji?
if(responseCode>=400) pwNF\ ={
{ QPB^%8
processErrorCode(responseCode); V:lKF')
return -2; //-2 represent access is error 2rM/kF >g
} IG!(q%Gf
y`pgJO
{7EpljH@
String sHeader; kU{a!ca4
,/dW*B
?4_ME3$t
for(int i=1;;i++) $WsyAUl
{ 3k:`7E.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1#|qT7
//Utility.log(in.readLine()); W O'nW
sHeader=httpConnection.getHeaderFieldKey(i); 'lOpoWDL
if(sHeader!=null) c']m5q39'
{ ZUl-&P_X
if(sHeader.equals("Content-Length")) ye4GHAm,p
{ iz27yXHZ~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ziv*4
break; p,3}A(>
} 352RJC
} Dp?lgw
else ,S&p\(r.
break; 4!-/m7%eF
} ah#jvp
} +*wo iSD
catch(IOException e){e.printStackTrace ();} :bqUA(k
catch(Exception e){e.printStackTrace ();} HHT8_c'CC#
U(hIT9
.cr<.Ov
Utility.log(nFileLength); {gB9EGY
K#R|GEwr
6U1_Wk?
return nFileLength; 2F/oWt|w?
} ~eXI}KhBw6
$?DEO[p.
:b,An'H
//保存下载信息（文件指针位置） n/%M9osF
private void write_nPos() )hD77(c
{ D_BdvWSxj
try{ {O4&HW%
output = new DataOutputStream(new FileOutputStream(tmpFile)); UXOf
output.writeInt(nStartPos.length); %kuUQ%W1
for(int i=0;i<nStartPos.length;i++) +)_#j/
{ jPs{Mr<
// output.writeLong(nPos); b.cBg.a
output.writeLong(fileSplitterFetch.nStartPos); 5 axt\
output.writeLong(fileSplitterFetch.nEndPos); H?;@r1ZAn
} u0%bv\$m
output.close(); Wp^A.
} af&P;#U
catch(IOException e){e.printStackTrace ();} O]t)`+%q
catch(Exception e){e.printStackTrace ();} }D!o=Mg^
} 5m?9O7Pg
Q5*"t*L!N
">q?(i\
//读取保存的下载信息（文件指针位置） P&*e\"{
private void read_nPos() 88l{M[B2
{ /mK]O7O7
try{ A$l
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3o#K8EL
int nCount = input.readInt(); eyos6Qi
nStartPos = new long[nCount]; 72= 4#
nEndPos = new long[nCount]; =h/61Bl3
for(int i=0;i<nStartPos.length;i++) ceae~
{ 8TYoa:pZ
nStartPos = input.readLong(); <m%ZDOMa
nEndPos = input.readLong(); ]G,BSttD
} ozl>Au
input.close(); w=[ITQ|W%
} {&nDm$KTD
catch(IOException e){e.printStackTrace ();} m(CsO|pz
catch(Exception e){e.printStackTrace ();} (w Q,($@
} L8KaK
.G>~xm0
t6~~s iQI'
private void processErrorCode(int nErrorCode) Q!h+1fb
{ y)3OQ24
System.err.println("Error Code : " + nErrorCode); b[MKo7
} B8>@q!G8P
5oo6d4[
nQG<OVRClS
//停止文件下载 yjM!M|
public void siteStop() ?&POVf>
{ 22`e7
bStop = true; e/$M6l$Q*4
for(int i=0;i<nStartPos.length;i++) ONLhQJCb
fileSplitterFetch.splitterStop(); YOtzja]~
1vCVTuRF
0SJ(Ln`0K
} c&"1Z/tR
} h@Ix9!?+
//负责部分文件的抓取 jgBJs^JgYG
**FileSplitterFetch.java wIF)(t-):
*/ \(U|&
package NetFox; hfs QAa
.GvZv>
{T3wOi
import java.io.*; 3(1UIu
import java.net.*; 4hW:c0
y.a)M?3
W2A!BaH%
public class FileSplitterFetch extends Thread { LWV^'B_X-
'r}y{`3M
#y1M1Og
String sURL; //File URL Jjh=zxR>
long nStartPos; //File Snippet Start Position $LtCI
long nEndPos; //File Snippet End Position >n%ckL|rG
int nThreadID; //Thread's ID Ee=!bv(%70
boolean bDownOver = false; //Downing is over iGNZC{
boolean bStop = false; //Stop identical 9<5ii
FileAccessI fileAccessI = null; //File Access interface h#uk-7
1(jx.W3
|2I/r$Q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @`HW0Y_:
{ aQV?}
this.sURL = sURL; 0VIR=Pbp
this.nStartPos = nStart; vSk1/
this.nEndPos = nEnd; % xBQX
nThreadID = id; }1NNXxQ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f_IsY+@
} N'?#g`*KW
K\5/||gi
ge%tj O
public void run() -c%'f&P
{ cZAf?,>u
while(nStartPos < nEndPos && !bStop) XKvH^Z4h{l
{ x'V:qv*O
ePTxuCf>
>vNE3S_
try{ 8[oZ>7LMzC
URL url = new URL(sURL); :PBW=W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m2Wi "X(I_
httpConnection.setRequestProperty("User-Agent","NetFox"); [\=1|t5n~
String sProperty = "bytes="+nStartPos+"-"; I%CrsEo
httpConnection.setRequestProperty("RANGE",sProperty); au/5`
Utility.log(sProperty); 'Ge8l%p
SI7r`'7A'
JY$;m3h
InputStream input = httpConnection.getInputStream(); yRt7&,}zL
//logResponseHead(httpConnection); MkM`)g 5
#X0Y8:vj
5zH_yZ@+
byte[] b = new byte[1024]; 3/8<dc
int nRead; Y5<W"[B!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :%IB34e
{ ^-(DokdBn
nStartPos += fileAccessI.write(b,0,nRead); }zrapL"9X
//if(nThreadID == 1) `|4k>5k
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `Cz_^>]|=
} KR>o 2
7~VDk5Z6
m5cRHo<9Y
Utility.log("Thread " + nThreadID + " is over!"); n"nfEA3{`
bDownOver = true; "FLiSz%ME
//nPos = fileAccessI.write (b,0,nRead); K/8TwB?I
} 4 Z&KR<2Z
catch(Exception e){e.printStackTrace ();} seZb;0
} ^_uCSA'X
} E*QLw*H
;+lsNf
VBK|*Tl
//打印回应的头信息 yER
public void logResponseHead(HttpURLConnection con) U=[isi+7
{ xn1, o MY=
for(int i=1;;i++) {X-a6OQj
{ d/\ajQ1::
String header=con.getHeaderFieldKey(i); !'>,37()
if(header!=null) +(h{3Y|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5e&;f
Utility.log(header+" : "+con.getHeaderField(header)); %.;;itB
else =|H.r9-PK6
break; }w{E<C(M
} x}#N?d
} 2g;Id.i>
i>(TPj|
/b410NP5
public void splitterStop() 1+qP7 3a^
{ uz;eYD
bStop = true; l6.&<0pLT
} ?3<Y/Vg%c
Fp>nu_-"
LXf|n
} 40 zO4
mcxD#+H 3
)QI#szv6
/* 7nZ3u_~
**FileAccess.java Nwk^r75lq
*//文件访问(定位，写) \Npvm49
package NetFox; ow#8oUf=
import java.io.*; ]N:Wt2
E|W7IgS
i\=I` Yn+
public class FileAccessI implements Serializable{ D0h6j0r5
C{,Vk/D-0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T75N0/teS
RandomAccessFile oSavedFile; 4K,S5^`Gx
long nPos; m,ur{B8 :
o 80x@ &A:
TNF
public FileAccessI() throws IOException \ZBz]rh*
{ \xmDkWzE
this("",0); _AH_<Z(
} <|hrmwk|
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zO0K*s.yK
public FileAccessI(String sName,long nPos) throws IOException kkXe=f%
{ {d> 6*b
oSavedFile = new RandomAccessFile(sName,"rw"); o Va[
this.nPos = nPos; bl\;*.s'
oSavedFile.seek(nPos); t;_1/mt
} (*\y
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@@=,bO
public synchronized int write(byte[] b,int nStart,int nLen) TW=N+ye^1(
{ {,= hIXo>
int n = -1; %Lq}5zB
try{ ypx`!2Q$
oSavedFile.write(b,nStart,nLen); A>\3FeU>UC
n = nLen; (R(NEN
} Bk5ft4v-
catch(IOException e) i*mI-l
{ }sp?@C,Z
e.printStackTrace (); AnpO?+\HF
} ,_K:DSiB
Uh'W d_?
/Z]hX*QR
return n; Fzz9BEw(i
} & d* bQv$
xM/WS':V
P1<McQ
} c)c_Qv
z2q!_ ~
U@:l~xJ
/* <"av /`;
**SiteInfoBean.java @.pr}S/
*/ 4I2#L+W
package NetFox; r>G||/Z
Zt 1nH
H7f Xg
public class SiteInfoBean { wV,=hMTd&\
qJw\<7m
!. :b}t
private String sSiteURL; //Site's URL ]-l4
private String sFilePath; //Saved File's Path 2~hQ
private String sFileName; //Saved File's Name s:I 8~Cc
private int nSplitter; //Count of Splited Downloading File JC}T*h>Ee
y8]vl;88yY
CS0q#?
public SiteInfoBean() 5'_:>0}
{//nSplitter的缺省值为5 kqGydGh*"
//default value of nSplitter is 5 0UQ DB5u
this("","","",5); m`jGBSlw_
} l I2UpfkBP
l>)+HoD
%m$t'?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ad4-aWH
{ |WW'qg]Uu
sSiteURL= sURL; OOYdrv,
sFilePath = sPath; Vc+~yh.)
sFileName = sName; ,,-j5Y
this.nSplitter = nSpiltter; M->#WGl\B
f|2QI~R
~O 4@b/!4
} 3w! NTvp
z'0 =3
S(:|S(
public String getSSiteURL() Az/P;C=
{ k0xm-
return sSiteURL; <<H'Z
} 9xL`i-7]
Htep3Ol3
1h`#H:
public void setSSiteURL(String value) fmFs
{ .L^F4
sSiteURL = value; Z*'_/Grv?
} z0T6a15f!P
qnO/4\qq
5'EoB^`8N~
public String getSFilePath() #:Ukv?
{ {3 >`k.w
return sFilePath; ,fj~BkW{
} T? ,Q=.
3)XS^WG
ca%XA|_J
public void setSFilePath(String value) EDg; s-T=
{ ,|w,
sFilePath = value; Wr,pm#gl6
} Qk&6Z%
fg GTm:
)XYCr<s2"
public String getSFileName() /1r{z1pv\
{ l Ng)k1
return sFileName; iF1zLI<A
} H)K.2Q
oB+@05m8
]Yf8
public void setSFileName(String value) pH0MVu(W
{ I2?g'tz
sFileName = value; Dj w#{WR
} 2F:X:f
z{qn|#}
Hlj3z3
public int getNSplitter() M2nZ,I=l
{ 'A/f>W
return nSplitter; x^ sTGd
} lsVg'k/Z!
~%sNPKjA
] .c$(.
public void setNSplitter(int nCount) qwo{34
{ ^0/!:*?
nSplitter = nCount; kqLpt
} 'he&h4fm
} x!UGLL]_M
?)4c!3#
Q>\9/DjUp
/* /-g%IeF
**Utility.java ;AT~?o`n
*/ ts=+k/Z
package NetFox; K?V' ?s
3 FLht L
2O`s'&.h
public class Utility { ;zi4W1
Gdlx0i
ae] hCWK
public Utility() J(`(PYo\i
{ aMyf|l.
~-NlTx
d C6t+
} o[nr)
qox@_
//线程睡眠 {-s7_\|p(
public static void sleep(int nSecond) MG$Df$R
{ #:nds,
try{ =UFmN"
Thread.sleep(nSecond); RaB%N$.9s
} n^rzl6dy
catch(Exception e) $p.0[A(N
{ Fh^Ax3P(
e.printStackTrace (); q7zHT=@$
} PL*kjrLu7
} vrXNa8,L
d~O)mJ J
//日志 m[&pR2T
public static void log(String sMsg) 9icy&'
{ :4S~}}N
System.err.println(sMsg); 5~xv"S(E}
} 4+au6ABy
/Y*6mQ:
U\;mM\2rE
public static void log(int sMsg) }I#,o!)Vd
{ Tv~Ys#
System.err.println(sMsg); XNB4KjT
} CGCSfoS9f
} I)f54AX
gK-$y9]~+
YnX6U1/^
/* I#](mRJ6
**TestMethod.java |?<r
*/ |dk9/xdX
package NetFox; = k>ygD_
2(NN QU@Uz
O`='8'6zW\
public class TestMethod { c|~f[
YN5p@b=FX
__,}/|K2
public TestMethod() @m ?&7{y#?
{ ///xx/weblogic60b2_win.exe O:te;lQK
try{ #Pq.^ ^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `Z~\&r=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JJE0q5[
SiteFileFetch fileFetch = new SiteFileFetch(bean); *qL"&h5W
fileFetch.start(); w_^g-P[o-
} Ck^jgB.7
catch(Exception e){e.printStackTrace ();} e{`DvfY21
v/}hy$7
C-L["O0[
} M9dUo7
|%7OI#t^
)\0LxsZ
public static void main(String[] args) tU(vt0~b
{ N+0`Jm
new TestMethod(); <!.Qn Y
} 5SmgE2}
} 1N\-Ku
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