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)); MI,b`pQ
} Q{~WWv
for(int i=0;i<nEndPos.length-1;i++) vA r fsgk
{ =d{B.BP(
nEndPos = nStartPos[i+1]; 9 Z5!3
} !Xzne_V<
nEndPos[nEndPos.length-1] = nFileLength; ? !dy
} DnZkZ;E/
} s$,gM,|cK
#J,?oe=<4
N5SePA\ ,?
//启动子线程 *C*'J7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; jM'kY|<g;
for(int i=0;i<nStartPos.length;i++) uV@#;c4
{ RzOs,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S-$N!G~!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :E>"z6H
nStartPos,nEndPos,i); tlnU2TT_f
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *QIlh""6
fileSplitterFetch.start(); 5ZXP$.
} D[NJ{E.{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1@}`dc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a->;K+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @Weim7r
nEndPos = " + nFileLength); 0^L>J"o
// fileSplitterFetch[nPos.length-1].start(); 007(k"=oV
5a PPq~%
~T{^7"q\
//等待子线程结束 ~'[0-_]=f
//int count = 0; m4<5jC`-M
//是否结束while循环 [f?fA[,[
boolean breakWhile = false; X(`wj~45VX
);]9M~$
`k 5'nnyP
while(!bStop) J ^y1=PM
{ IYo{eX~=
write_nPos(); =u5a'bp0;;
Utility.sleep(500); 9uNkd2#
breakWhile = true; kma)DW
/5l"rni
!Rq.L
for(int i=0;i<nStartPos.length;i++) 1TagQ
{ <yw6Om:n<
if(!fileSplitterFetch.bDownOver) xE2sb*
{ &RzkM4"
breakWhile = false; =nQgS.D
break; 'nrXRDb
} gB;5&;T:
} #%;QcDXRe
if(breakWhile) 5 +Ei!E89
break; eYN=?
/*zngp@
)nK-39,G
//count++; I:ag}L8`
//if(count>4) r}-si^fo;
// siteStop(); e#+u8LrN
} '\MYC8"
sUCI+)cM3
_\d[`7#
System.err.println("文件下载结束！"); )tq&l>0h
} _XO3ml\x@
catch(Exception e){e.printStackTrace ();} Mj guH5Uy
} JBYmy_Su
%z0;77[1I
2~*J<iO&l
//获得文件长度 C V{kP8#
public long getFileSize() . paA0j
{ 1kd\Fq^z$
int nFileLength = -1; ]WsQ=
try{ ]~Su
URL url = new URL(siteInfoBean.getSSiteURL()); Aa.eu=@I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *t)Y@=k3>
httpConnection.setRequestProperty("User-Agent","NetFox"); p-6Y5$Y
\-]zXKl2k
?=bqya"Y
int responseCode=httpConnection.getResponseCode(); va>u1S<lO
if(responseCode>=400) 6/%dD DU
{ kK0.j)(
processErrorCode(responseCode); Q|DVB
return -2; //-2 represent access is error e={X{5z0
} xzZ2?zWi
e2~$=f-
bvxol\7;
String sHeader; @d+NeS
,EE,W0/zzM
YR 5C`o
for(int i=1;;i++) P1r)n{;
{ vky@L!&,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); D<16m<b
//Utility.log(in.readLine()); ,esryFRG
sHeader=httpConnection.getHeaderFieldKey(i); K4G43P5q`
if(sHeader!=null) B$Z%_j&
{ Qb.Ve7c
if(sHeader.equals("Content-Length")) QGR}`n2D
{ ag_RKlM3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k Y}r^NaQA
break; W<QMUu
} q)m0n237P
} RjcU0$Hi
else )V6Bzn}9
break; DV8b<)
} +2KYtyI
} Ao0p=@Y
catch(IOException e){e.printStackTrace ();} ~$WBcqo
catch(Exception e){e.printStackTrace ();} c\J?J>xz
!Qqi%
+nz6+{li\
Utility.log(nFileLength); 61[ 8I},V
+.EP_2f9
Az`c? W%
return nFileLength; UdiogXZ
} ,:E*Mw:
__3s3YG
NrVE[Z#
//保存下载信息（文件指针位置） )'+ tb\g
private void write_nPos() G2 E4
{ 9W7 ljUg
try{ Wq+a5[3"
output = new DataOutputStream(new FileOutputStream(tmpFile)); wm'a)B?
output.writeInt(nStartPos.length); t1Zcr#b>
for(int i=0;i<nStartPos.length;i++) ~YH'&L.O
{ 3w>S?"W#
// output.writeLong(nPos); kL7n`o
output.writeLong(fileSplitterFetch.nStartPos); #Ns]l<
output.writeLong(fileSplitterFetch.nEndPos); ]UMt
} f*:DH4g }B
output.close(); |h7 d#V>
} &2P+9j>
catch(IOException e){e.printStackTrace ();} M3 TsalF
catch(Exception e){e.printStackTrace ();} xk#q_!(j
} w|k?2 ?&
~fht [S?@M
v>[U*E
//读取保存的下载信息（文件指针位置） >,9ah"K_x
private void read_nPos() <27:O,I
{ -K@mjN
try{ VqIzDs
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); OxC8xB;`
int nCount = input.readInt(); 1Mtm?3Pt
nStartPos = new long[nCount]; q;)+O#CR
nEndPos = new long[nCount]; 4ZX6=-u^
for(int i=0;i<nStartPos.length;i++) sU=7)*$
{ w<P$)~6
nStartPos = input.readLong(); \{@n>Mh
nEndPos = input.readLong(); XaxM$
} 5fT"`FL?
input.close(); gB)Cmw*
} .,9e~6}
catch(IOException e){e.printStackTrace ();} :f/T$fa*
catch(Exception e){e.printStackTrace ();} "C/X#y
} ,O'#7Dj
nn?h;KzB
XzD+#+By
private void processErrorCode(int nErrorCode) l} =@9A@
{ b)(rlX
System.err.println("Error Code : " + nErrorCode); L|*0 A=6
} Gpb<,v_3
F*, e,s
k0(_0o
//停止文件下载 |lG7/\A
public void siteStop() ea3f`z
{ SmUj8?6"
bStop = true; ;]PP+h
for(int i=0;i<nStartPos.length;i++) ^Mmsja5K
fileSplitterFetch.splitterStop(); Oj,v88=
51Q m2,P1^
gy*c$[NS$
} %jErLg
} 8JFvz(SK>
//负责部分文件的抓取 4/?@%
**FileSplitterFetch.java ecsQshR
*/ Re<@.d
package NetFox; |6O7_U#q
m5_
<C<z#M'`
import java.io.*; ~#];&WE
import java.net.*; B~h3naSe
_g2"D[I%
*mjPNp'3{m
public class FileSplitterFetch extends Thread { N!~5S`
W'Y?X]xr
}Sr=|j
String sURL; //File URL AeR*79x
long nStartPos; //File Snippet Start Position bn#'o(Lp
long nEndPos; //File Snippet End Position p&$O}AX|
int nThreadID; //Thread's ID fWz=bJ"V
boolean bDownOver = false; //Downing is over eq6>C7.$
boolean bStop = false; //Stop identical VxAG=E
FileAccessI fileAccessI = null; //File Access interface V]5MIiNl
oiTSpd-
h3rVa6cxM
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QF4)@ r{2x
{ 9q]n&5
this.sURL = sURL; ?P%-p
this.nStartPos = nStart; % 4Gt^:J"
this.nEndPos = nEnd; d^+0=_[PmK
nThreadID = id; Mpx98xcO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Kn*LwWne
} 5kik+
&Sdf0"
[C`LKA$t
public void run() <]f{X<ef
{ cw/E?0MWb
while(nStartPos < nEndPos && !bStop) +'0V6\y
{ O)8$aAJ)V
&[7z:`+Y##
AaLbJYuKd
try{ rcAPp
URL url = new URL(sURL); ;Xl {m`E+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FI"KJk'
httpConnection.setRequestProperty("User-Agent","NetFox"); M3VTzwuf^S
String sProperty = "bytes="+nStartPos+"-"; `>Ms7G9S~e
httpConnection.setRequestProperty("RANGE",sProperty); -xVZm8y
Utility.log(sProperty); W P9PX
hYbaVE
nt_FqUJ
InputStream input = httpConnection.getInputStream(); W+I""I*mV
//logResponseHead(httpConnection); bk|?>yd
!<vy!pXg
/d*[za'0
byte[] b = new byte[1024]; p5aqlYb6r
int nRead; $U4[a:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &>xz
{ ]YrgkC35
nStartPos += fileAccessI.write(b,0,nRead); 9T_fq56Oh6
//if(nThreadID == 1) rtdEIk
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Pm"nwm
} OK(xG3T
~X(2F#{<{
L0;XzZS
Utility.log("Thread " + nThreadID + " is over!"); ~5o2jTNy`p
bDownOver = true; F<4>g+Ag
//nPos = fileAccessI.write (b,0,nRead); D]twid~OS
} K]&i9`>N
catch(Exception e){e.printStackTrace ();} }Ud'j'QMy
} Ce/D[%
} /V }Z,'+
FA{'Ki`
meYGIP:n
//打印回应的头信息 v,!`A!{D
public void logResponseHead(HttpURLConnection con) *G8Z[ht%r
{ Zg9VkL6Z6
for(int i=1;;i++) 5fy{!
{ uN=f(-"
String header=con.getHeaderFieldKey(i); aMJJ|iiU
if(header!=null) vDIsawbHD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QIfP%,LT
Utility.log(header+" : "+con.getHeaderField(header)); 88VI _<
else /*(&Dmt>
break; D67z6jep(
} Md&K#)9,(
} r72zWpF!Ss
b%].D(qBy
7ufTmz#j<
public void splitterStop() `SA1V),~
{ P2F8[o!<
bStop = true; _:>t$* _
} (6i4N2
40O@a:q*
q2U?EP{8~
} 32Wa{LG;2
a4mRu|x
LK<ZF=z]Z
/* ^O& y;5
**FileAccess.java MaLH2?je^n
*//文件访问(定位，写) 'Hsd7Dpi}
package NetFox; n5y0$S/D
import java.io.*; 11%Zx3
}:S}jo7
t$b5,"G1
public class FileAccessI implements Serializable{ I#'yy7J
DiskGq@T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c`/kx
RandomAccessFile oSavedFile; Mp(;PbVD
long nPos; ';m;K (g
l=L(pS3 ~
S{Zf}8?6$
public FileAccessI() throws IOException iI3,q-LA
{ Z`#XB2,
this("",0); <B'PB"R3y
} +UiJWO
n(.L=VuXn
\0Ba?
public FileAccessI(String sName,long nPos) throws IOException [<sN"
{ fNV-_^,R9
oSavedFile = new RandomAccessFile(sName,"rw"); *;l[|
this.nPos = nPos; 7=s7dYlu
oSavedFile.seek(nPos); kG5Uc83#G
} "-\8Y>E
owwWm1@
5lyHg{iqD
public synchronized int write(byte[] b,int nStart,int nLen) %~M#3Ywa
{ ]G^9PZ-
int n = -1; l5D4?`|
try{ GcG$>&,
oSavedFile.write(b,nStart,nLen); xEv?2n@A
n = nLen; `NNP}O2
} =}0$|@pl
catch(IOException e) Gz4LjMQ &
{ 7eW6$$ju,N
e.printStackTrace (); C}ASVywc,1
} Qjd]BX;
^V7)V)Z;0
|pBvy1e4)
return n; t^2$ent
} :(4q\~
!r9rTS]
?X Rl\V
} !}sF#
R+2~%|{d
],{M``]q
/* U;*O7K=P
**SiteInfoBean.java ce*?crOV
*/ Kw2]J)TO
package NetFox; `6BQ6)7
Wz#ZkNO
g`~;"%u7cn
public class SiteInfoBean { 2wa'WEx
Io tc>!
D&pp <
private String sSiteURL; //Site's URL ..w$p-1
private String sFilePath; //Saved File's Path " t?44[
private String sFileName; //Saved File's Name Hz=s)6$ey
private int nSplitter; //Count of Splited Downloading File *?VB/yO=0
~6+Um_A_L
w ~^{V4V
public SiteInfoBean() orbz`IQc
{//nSplitter的缺省值为5 JSx[V<7m
//default value of nSplitter is 5 7PwH&rI
this("","","",5); Ocz21gl-?`
} )|#ExyRO
cQsSJBZ[v5
]:m4~0^#-(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) MP.ye|i4Q
{ Kjpsz];
sSiteURL= sURL; lTVz'ys
sFilePath = sPath; FC
sFileName = sName; N34bB>_
this.nSplitter = nSpiltter; d[*NDMO
:&LV^A
"ZA`Lp;%w
} _ q AT%.
~f( #S*Ic
s>[Oe|`
public String getSSiteURL() =h|7bYLy
{ )\kNufP
return sSiteURL; t~.^92]s|
} ad9u;uS
s@Loax6@B
+UX} "m~W
public void setSSiteURL(String value) ?}S!8;d
{ 6WoFf
sSiteURL = value; wUfPnAD.'
} E^m)&.+'M
/<dl"PWkJv
C;#gy-
public String getSFilePath() P7REE_<1
{ }=.C~f]A
return sFilePath; ca,c+5
} c{39,oF
)q/brCq
xK4E+^ b
public void setSFilePath(String value) |CK/-UG}
{ k^K%."INn
sFilePath = value; B B^81{A
} SRU#Y8Xv|
1v<uA9A%[
W .Al\!Gi
public String getSFileName() V8b^{}nxt
{ 1^[]#N-Bu
return sFileName; R;uP^
} Q8]S6,pt
~q}]/0-m
pW>.3pj
public void setSFileName(String value) :5jorVu
{ 23opaX5V=
sFileName = value; @V@<j)3P
} 9WHarv2@
]eX(K5 A
7t78=wpLc
public int getNSplitter() !\5)!B
{ 'b+ Tio
return nSplitter; `8TL*.9
} E~8J<gE
z5sKV7&\[n
-qLNs_ _k
public void setNSplitter(int nCount) %6Y}0>gY
{ @[n%q.|VB
nSplitter = nCount; EJJ&`,q
} B*^QTJ
} L:jv%;DM
F$9+WS`c
2%MS$Fto
/* +!G)N~o
**Utility.java MW=rX>tE
*/ tMo=q7ig
package NetFox; APU~y5vG (
k_Lv\'Ok
HDz"i
public class Utility { 9'KOc5@l^
=S\pI
:z$+leNH\
public Utility() 8P&z@E{y
{ Qr?(2t#
0.1?hb|p5T
9Dyy&$s
} q@Zeu\T,*#
nzU0=w}V
//线程睡眠 9FF
public static void sleep(int nSecond) ^a#W|-:
{ 4hn'b[
try{ RVpo,;:
Thread.sleep(nSecond); C4|79UG>s
} j"&Oa&SH
catch(Exception e) ,ZnL38GW
{ lnV!Xuf
e.printStackTrace (); cQ0+kX<
} cWI7];/d;
} 5)gC<
a JQ_V
//日志 2}5@:cwR+
public static void log(String sMsg) YCyh+%Q(
{ mH'om SCz
System.err.println(sMsg); (]5gYi
} s]xn&rd_
`>0(N.'T
|Lc.XxBkc
public static void log(int sMsg) 5g2:o^
{ l585L3i
System.err.println(sMsg); 0rc'SEl
} jfZ)
} _~!c%_
@rr\Jf""z
hr g'Z5n
/* ;]2d%Qt
**TestMethod.java x0xQFlGk
*/ IN"6=2:
package NetFox; |(9l_e|
Jz-RMX=
&3P"l.j
public class TestMethod { c2yZvi
Angt=q
-V||1@ |
public TestMethod() s6I/%R3
{ ///xx/weblogic60b2_win.exe ) =|8%IrB
try{ =8DS~J{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Oq95zo
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); DF"*[]^[
SiteFileFetch fileFetch = new SiteFileFetch(bean); So#>x5dL
fileFetch.start(); z>spRl,dr
} Kq:vTz&<
catch(Exception e){e.printStackTrace ();} '8|joj>G=
U2(mWQ[mO
\%.&$z3wz
} *(nu0
Bo/i =/7%
8ya|eJ]/L
public static void main(String[] args) qnw8#!%I
{ (z%OK[
new TestMethod(); Qs_]U
} |PLWF[+t8
} "T6s;'k
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