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)); ^"O{o8l>2
} Sa;<B:|
for(int i=0;i<nEndPos.length-1;i++) IpWy)B>Fl3
{ 4d^ \l!
nEndPos = nStartPos[i+1]; yV:EK{E
} ]6t]m2~\
nEndPos[nEndPos.length-1] = nFileLength; *L%6qxl`V
} 7Wwp )D
} eVw\v#gd
N5 SLF4R1
bBUbw*DF)
//启动子线程 E`Jp(gK9F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9wO/?
for(int i=0;i<nStartPos.length;i++) 2;r]gT~
{ |SGgy|/a#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r0\cc6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cGgM8
nStartPos,nEndPos,i); uY^v"cw/F
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (jU/Wj!q
fileSplitterFetch.start(); ]y3pE}R
} ]\CU9J|H8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <^lJr82
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [YC=d1F5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I jZ]_*^!
nEndPos = " + nFileLength); t)-*.qZh
// fileSplitterFetch[nPos.length-1].start(); uYFMv=>j
3B@y &a#&
Jy \2I{I'
//等待子线程结束 Z?m -&%
//int count = 0; `J72+RA
//是否结束while循环 G1]"s@8(
boolean breakWhile = false; 3`8dii
N>+P WE$
<,\ `Psa)N
while(!bStop) `AWy!}8
{ a%Uw;6|{
write_nPos(); <&4nOt
Utility.sleep(500); p6`Pp"J_tr
breakWhile = true; B?+.2
G+0><,S
M'kVL0p?vN
for(int i=0;i<nStartPos.length;i++) $:Rn;
{ vt//)*(.$
if(!fileSplitterFetch.bDownOver) BR+nL6sU
{ rJ'/\Hh5P
breakWhile = false; 7 _`L$<-n
break; lWW+5
} COR;e`%,
} OFA{ KZga
if(breakWhile) a Sf/4\
break; c! @F
;x-(kIiE
g& k58{e
//count++; Frk cO
//if(count>4) L'lF/qe^
// siteStop(); Cezh l
} $(ewk):
[QT1Ju64
9M_(He -
System.err.println("文件下载结束！"); +iy7e6P
} EeB ]X24
catch(Exception e){e.printStackTrace ();} RPVT*`o
} 77V .["=7
oBA`|yW{U
B$^7h!
//获得文件长度 H6gU?9%
public long getFileSize() V }>n
{ Y>BP?l
int nFileLength = -1; $<|ocUC7
try{ nBN&.+3t
URL url = new URL(siteInfoBean.getSSiteURL()); K^zDNIQU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q]\X~ 9#
httpConnection.setRequestProperty("User-Agent","NetFox"); *:_P8G;
w(j^ccPD
Tr& }$kird
int responseCode=httpConnection.getResponseCode(); ;gMgj$mI
if(responseCode>=400) B6]<G-
{ [iS,#w` 5
processErrorCode(responseCode); 8!mc@$Z
return -2; //-2 represent access is error fQ+\;iAU
} BByCMY
auHFir8f
2 -Xdoxw
String sHeader; f?56=& pHY
N j4IQ<OV
|>2FRPK
for(int i=1;;i++) |.P/:e9
{ 7\XE,;4>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K>2#UzW
//Utility.log(in.readLine()); Sm-wH^~KA
sHeader=httpConnection.getHeaderFieldKey(i); "&~ 0T#
if(sHeader!=null) >u0w.3r#
{ 8' K0L(3[
if(sHeader.equals("Content-Length")) ceT&Y{T
{ M+`Hg_#Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (*\jbK
break; BVw Wj-,
} pV(lhDNoQ
} ]3Dl)[R
else q o 1lj"P
break; 7@}$|u:JUF
} fP HLXg5s
} ;WU<CKYG*
catch(IOException e){e.printStackTrace ();} CHJ>{b`O
catch(Exception e){e.printStackTrace ();} awewYf$li
j'0r'
,8MLoZ_
Utility.log(nFileLength); &o3K%M;C?
]i*](UQ
%\$;(#h
return nFileLength; Zm ogM7B
} p4K.NdUH
m~hoE8C$
o>/O++7Ra
//保存下载信息（文件指针位置） 8>WVodv
private void write_nPos() v%{.A)
{ f.B>&%JRZ
try{ 7OCwG~_^
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1xE]6he4{T
output.writeInt(nStartPos.length); ]iNEw9
for(int i=0;i<nStartPos.length;i++) k n[Y
{ k>jbcSY(z<
// output.writeLong(nPos); 6$fYt&1
output.writeLong(fileSplitterFetch.nStartPos); eM7Bc4V
output.writeLong(fileSplitterFetch.nEndPos); R9rj/Co
} aVL=K
output.close(); ^D`v3d
} NcPgq?3p
catch(IOException e){e.printStackTrace ();} !HeSOzN
catch(Exception e){e.printStackTrace ();} ^ci3F<?Q=
} Cxod[$8
E37<"(;
*'Y@3vKE
//读取保存的下载信息（文件指针位置） !+)AeDc:j
private void read_nPos() sVk$x:k1M
{ bwM@/g%DL
try{ h7*W*Bd
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~_IHaw$hg
int nCount = input.readInt(); p Dx-2:}
nStartPos = new long[nCount]; =0;}K@(J
nEndPos = new long[nCount]; 'bld,Do6
for(int i=0;i<nStartPos.length;i++) :c9U>1`g&
{ n+lOb
nStartPos = input.readLong(); iRg7*MQu
nEndPos = input.readLong(); ^<e@uNGg
} i wxVl)QL
input.close(); :ISMPe3'
} T,xPSN2A*
catch(IOException e){e.printStackTrace ();} \0lnxLA
catch(Exception e){e.printStackTrace ();} t5)+&I2
} bY}eUL2i4
ae:zWk'!
7\*FEjRM]
private void processErrorCode(int nErrorCode) )X9W y!w0
{ %sHF-n5P
System.err.println("Error Code : " + nErrorCode); X#3et'
} &E xYXI
OpM(j&
WDFjp
//停止文件下载 (b'B%rFO
public void siteStop() VJ ^dY;
{ 2I*;A5$N1
bStop = true; :qChMU|Y6
for(int i=0;i<nStartPos.length;i++) 8-y{a.,u.
fileSplitterFetch.splitterStop(); !mWiYpbU+
,g%&|FAP
'*\|;l#1
} Dfq(Iv
} ^Y-]*8;]
//负责部分文件的抓取 h?bb/T+'
**FileSplitterFetch.java Ag F,aZU
*/ 8,0YD#x
package NetFox; DW)2 m;
P!"&%d
U|g:`v7
import java.io.*; u%~igt@x
import java.net.*; ]4;PR("aU
>A@Y$.
,V*%V;
public class FileSplitterFetch extends Thread { gJ2>(k03y
sP^R/z|Y
;FZ@:%qDm
String sURL; //File URL kOh{l: 2-+
long nStartPos; //File Snippet Start Position f>aRkTHf
long nEndPos; //File Snippet End Position gY@N~'f;"
int nThreadID; //Thread's ID wn)JXR
boolean bDownOver = false; //Downing is over 6xD#?
boolean bStop = false; //Stop identical 1Bpv"67
FileAccessI fileAccessI = null; //File Access interface Ur*6Gi6
=m5SK5vLKT
IpP~Uz
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?B:a|0pf
{ ;|UF)QGa2
this.sURL = sURL; 271&i
this.nStartPos = nStart; I4&::y^C
this.nEndPos = nEnd; 0{#8',*}m?
nThreadID = id; LVJxn2x6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h,Q3oy\s1
} uL[.ND2._&
PssMTEf
8P=o4lO+
public void run() {'U Rz[g
{ sP ls zC[
while(nStartPos < nEndPos && !bStop) =b/L?dR.-
{ rL}YLR
RIIitgV_
\?jeWyo
try{ ij?
URL url = new URL(sURL); /{|fyKo\?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cq$i
httpConnection.setRequestProperty("User-Agent","NetFox"); &gjF4~W]
String sProperty = "bytes="+nStartPos+"-"; XP@1~$
httpConnection.setRequestProperty("RANGE",sProperty); )KP5WudX
Utility.log(sProperty); P{u0ftyX}
e[8LmuIZ
5|1T}Z#;
InputStream input = httpConnection.getInputStream(); Ox@sI:CT
//logResponseHead(httpConnection); ~q~MoN<R
CxfRVL`7
U4cY_p?
byte[] b = new byte[1024]; Q9Q|lO
int nRead; A,`8#-AX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) f"St&q>[s
{ O9r>E3-q
nStartPos += fileAccessI.write(b,0,nRead); HQB(*
//if(nThreadID == 1) 0X^Ke(/89
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z(H^..<!5
} Ybn`3
pZeE61c/
?]x|Zy
Utility.log("Thread " + nThreadID + " is over!"); K3=3~uY
bDownOver = true; (<)]sp2
//nPos = fileAccessI.write (b,0,nRead); SXy=<%ed
} /"B?1?qc,=
catch(Exception e){e.printStackTrace ();} 0$-xw
} 4 M(-xl?
} k70|'*Kh
[3@):8
$ mI0Bk
//打印回应的头信息 CXC`sPY
public void logResponseHead(HttpURLConnection con) &cu lbcz
{ 3Oi nK['
for(int i=1;;i++) YiPoYlD*n<
{ 3:C oZ
String header=con.getHeaderFieldKey(i); }6@pJG
if(header!=null) nG;8:f`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GxKqD;;u?=
Utility.log(header+" : "+con.getHeaderField(header)); ;dzL}@we
else }5(Ho$S(
break; DrO2y
} EcCFbqS4W
} /;utcc
67VT\f
o5Q{/
public void splitterStop() +*hm-lv?
{ T16{_
bStop = true; :at$HCaK
} R<=zCE`:
EMfdBY5
!H}vu]R
} n2fbp\I
ZAXN6h
,.qMEMm
/* yfC^x%d7G
**FileAccess.java 1Q.\s_2
*//文件访问(定位，写) |\g5+fv9
package NetFox; L_K=g_]
import java.io.*; |e2be1LD
XQ~Ke-QW)
ti<;7Yb
public class FileAccessI implements Serializable{ 1 %,a =,v
S!sqbLrBn
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &JtV'@>v
RandomAccessFile oSavedFile; $O*O/iG
long nPos; ;j)FnY=:-
+fnK/%b
QQV~?iW{~
public FileAccessI() throws IOException xQ'2BAEa
{ oI#a_/w
this("",0); v= N!SaK{
} Q;D0<Bv
Jzp#bgq}|
u3o#{~E/#
public FileAccessI(String sName,long nPos) throws IOException pm9%%M$
{ [o<VVtB.Gk
oSavedFile = new RandomAccessFile(sName,"rw"); D2,z)O%VK
this.nPos = nPos; bHI<B)=`
oSavedFile.seek(nPos); leQT-l2Bk
} e~"fn*"
%bdjBa}
4DOK4{4?5
public synchronized int write(byte[] b,int nStart,int nLen) M_%B|S {
{ m{7(PHpw
int n = -1; r]0 lo-
try{ jH6&q~#
oSavedFile.write(b,nStart,nLen); DzheoA-+L'
n = nLen; pm6>_Kz
} D91e\|]
catch(IOException e) oy;K_9\
{ LvEnXS
e.printStackTrace (); ykFJ%sw3X
} po}F6m8bX
C*G=cs\i
xrN &N_K#
return n; i>joT><B
} o^V(U~m]
MG?0>^F
g9Yz*Nee<
} +nT'I!//
<u=4*:QE
1=]kWp`i
/* XJIv1s\g
**SiteInfoBean.java Jx=hJ-FY
*/ W'on$mB5<
package NetFox; 84{Q\c
E{2Eoj;gq
EutP\K_Y
public class SiteInfoBean { 9Mgq1Z
-uH#VP{0M
XhPe]P
private String sSiteURL; //Site's URL aceZ3U>W
private String sFilePath; //Saved File's Path *;XWLd#
private String sFileName; //Saved File's Name U-^[lWn[@4
private int nSplitter; //Count of Splited Downloading File )aX2jSp
8#&q$kE
Gx 72
public SiteInfoBean() Q_vW3xz
{//nSplitter的缺省值为5 @K:N,@yq
//default value of nSplitter is 5 BJS-Jy$-
this("","","",5); efY8M2
} 3! ~K^Z]
[>|FB'
2:LHy[{5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) T{}fHfM
{ d HJhFw
sSiteURL= sURL; :ZDMNhUl &
sFilePath = sPath; !7d*v3)d
sFileName = sName; hwqbi "o
this.nSplitter = nSpiltter; Y+qQIMZ
-!({BH-M_
6yy;JQAke
} dC<LDxlv
"<i SZ
)RsM!}
public String getSSiteURL() jn.C|9/mj
{ LG]3hz9^9
return sSiteURL; rbZ[!LA
} ?U7) XvQ
-]:GL>b
fj,m
public void setSSiteURL(String value) ai*b:Q
{ O3o: qly!
sSiteURL = value; voe7l+Xk
} m%#`y\]I
`8\Ja$ =
(.3'=n|kE
public String getSFilePath() =xianQ<lK
{ jKIc09H|
return sFilePath; e&9F\e
} tD$lNh^
iK_c.b
OJb*VtZz5R
public void setSFilePath(String value) Ov82ibp_1
{ 5f:DN\ ]
sFilePath = value; K^t?gt@k}
} sn{AwF%
VK3it3FI>3
Wd(86idnc
public String getSFileName() as"N=\N
{ )$x_!=@1
return sFileName; 'YSuQP>
} !~-6wN"k
Dmdy=&G
<1~^C
public void setSFileName(String value) `xKFqx:e
{ G.U5)4_^
sFileName = value; o'%eI
} Ps R>V)L
v@EQ^C2.&
2}t&iG|0/
public int getNSplitter() \.s`n2.w
{ HT`1E0G8)
return nSplitter; 'i>xf ^
} 0&fl#]oCE
mxqG-*ch-
#%S0PL"x U
public void setNSplitter(int nCount) Q*O<@
{ `EMi0hm&H
nSplitter = nCount; +3^NaY`Y
} ^i_Iqph=
} %"Db?
G5'_a$
<`g3(?
/* )fh0&Y; R
**Utility.java F;D1F+S
*/ C9KWa*3
package NetFox; /r.6XZs6
z \?UGxu}
?~2Bi^W5
public class Utility { Q;26V4
Rrqg[F+
m4/}Jx[
public Utility() :):zNn_>`
{ /)V4k:#b
uu}-"/<~7
Jyu`-=It
} (@]tG?I=
<d@pmh
//线程睡眠 C{Blqf3V0
public static void sleep(int nSecond) :)P<jX-G
{ |< N frz
try{ 4MX7=!E
Thread.sleep(nSecond); v["3
} ac6*v49
catch(Exception e) .[f;(WR
{ JE)J<9gf
e.printStackTrace (); oCJbkt=
} Fp:3#Bh
} ?~)Ak`=
my,x9UPs
//日志 G?[-cNdk
public static void log(String sMsg) P^(.tr3t
{ MFTC6L+T
System.err.println(sMsg); C ktX0
} WEVl9]b'e+
pbdF]>\
6_ ]8\n
public static void log(int sMsg) &"AQ;%&N
{ sV'v* 1|
System.err.println(sMsg); <bX 1,}?
} KW>VOW<.
} 'bm:u
AP ;*iyQ[
6UI>GQ
/* ;KS`,<^-
**TestMethod.java 6EP~F8Kd
*/ xOM_R2Md
package NetFox; x3;jWg~'
_3U|2(E
-eq=4N=s
public class TestMethod { x-4J/tm
H%~Q?4
iUCwKpb9
public TestMethod() (uT^Nn9L=
{ ///xx/weblogic60b2_win.exe 6puVw-X
try{ r\bq[9dX>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [,nfAY
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -3`Isv
SiteFileFetch fileFetch = new SiteFileFetch(bean); _r7=&oL.Q
fileFetch.start(); /KP_Vc:g2_
} @?vLAsp\
catch(Exception e){e.printStackTrace ();} ,W8au"
!*8#jy
'XEK&Yi1
} #Wq#beBb
-sx-7LKi
excrXx
public static void main(String[] args) `:R-[>5P8
{ ^^'[%ok
new TestMethod(); fX""xTNPi
} -D;lS 6
} !rz)bd3$
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