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)); [$mHv,~
} {#ZlM
for(int i=0;i<nEndPos.length-1;i++) *:Y%HAy*
{ RSfQNc9Z
nEndPos = nStartPos[i+1]; 2GP=&K/A
} PC~Y8,A|.t
nEndPos[nEndPos.length-1] = nFileLength; ,|3MG",@@h
} ^X=arTE
} &*##bA"!B
<fZyAa3}
?^7t'`zk
//启动子线程 aRj9E}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $Ipg&`S"
for(int i=0;i<nStartPos.length;i++) Njxv4cc
{ Z_$%.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C^O VB-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =O&%c%~q
nStartPos,nEndPos,i); $mu^G t
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *1uKr9
fileSplitterFetch.start(); o*-)Tq8GHE
} U_M$#i{_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z?6%;n^ 54
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @3) (BpFe
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qyZ" %Kz
nEndPos = " + nFileLength); =b%MXT
// fileSplitterFetch[nPos.length-1].start(); 1a?!@g)
O9G[j=U
*{YlN}vA
//等待子线程结束 \z>fb%YW
//int count = 0; q3mJ782p]
//是否结束while循环 @:j}Jmg
boolean breakWhile = false; aT{_0m$G10
MDnKX?Y
CnU*Jb
while(!bStop) u8'Zl8g
{ |nc@"OJ
write_nPos(); H['N
Utility.sleep(500); Vy6qbC-Kt
breakWhile = true; wrc,b{{[iM
^&B@Uw5{
"7 4-4
for(int i=0;i<nStartPos.length;i++) dz:E?
{ h:W;^\J:-
if(!fileSplitterFetch.bDownOver) riUwBiVa?2
{ >W%EmnLK
breakWhile = false; A}BVep@D
break; +O"!qAiK
} u7Y WnD
} .t{MIC
if(breakWhile) o\[~.";Z
break; |WQBDB`W
]q;Emy
@fHi\W2JG
//count++; PxTwPl
//if(count>4) u#Pa7_zBj]
// siteStop(); srr :!5
} |v`AA?@{8
}K7#Q
GD&uQ`Y5
System.err.println("文件下载结束！"); _64A(U
} Za/-i"U
catch(Exception e){e.printStackTrace ();} /@wg>&L]
} DjCqh-&L
bZ?v-fn\D,
+M./@U*g
//获得文件长度 c#XXp"7k2
public long getFileSize() !-z'2B*:^
{ 9`T)@Uj2n
int nFileLength = -1; HD@$t)mn
try{ )YYf1o[+
URL url = new URL(siteInfoBean.getSSiteURL()); )#EGTRdo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g%ndvdb m
httpConnection.setRequestProperty("User-Agent","NetFox"); yd^{tQi
+@A
v6[!o<@"a
int responseCode=httpConnection.getResponseCode(); c%^7!FSg
if(responseCode>=400) 7G:s2432
{ AhCW'.
processErrorCode(responseCode); g9m-TkNk
return -2; //-2 represent access is error 10G}{
} ZEXc%-M
-0d0t!
_- [''(E
String sHeader; o906/5M
bH-ub2@qO
P#E&|n7DT
for(int i=1;;i++) Yab%/z2:
{ q YC;cKv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {i1|R"ta
//Utility.log(in.readLine()); !xzeMVI
sHeader=httpConnection.getHeaderFieldKey(i); O6Vtu Ws%
if(sHeader!=null) $CxKuB(
{ BIb4h
if(sHeader.equals("Content-Length")) $Ad{Z
{ N@;?CKU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -<c=US
break; jTf@l?|
} CHdX;'`*
} 8&;UO{
else _ ?TN;
break; \(~y?l
} xqXo0
} ~fBtQGdX
catch(IOException e){e.printStackTrace ();} ^aIPN5CK
catch(Exception e){e.printStackTrace ();} +y,T4^{
OGBHos
"HX<,l8f%
Utility.log(nFileLength); Qf58ig-vCY
zUDg&-J3
Hh%I0#
return nFileLength; Jx_cf9{
} 9lTv
,K>I%_!1
y6@0O%TDN
//保存下载信息（文件指针位置） Q0$8j-1I
private void write_nPos() T`/AY?#
{ >@BnV{ d
try{ ,V'o4]H
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,4hJT
output.writeInt(nStartPos.length); he#J|p
for(int i=0;i<nStartPos.length;i++) H12Fw'2
{ h-g+g#*
// output.writeLong(nPos); ke{8 ^X~#
output.writeLong(fileSplitterFetch.nStartPos); 7t3X)Ah
output.writeLong(fileSplitterFetch.nEndPos); |VKK#J/
} C#QpQg2
output.close(); rI{=WPI&WU
} "B8Q:
catch(IOException e){e.printStackTrace ();} TbA}BFT`
catch(Exception e){e.printStackTrace ();} D,m]CK'
} ;1#H62Z*
c@YI;HS_g
gep;{G}
//读取保存的下载信息（文件指针位置） *v?`<)P#
private void read_nPos() du+y5dw
{ k2E0/ @f{k
try{ zFfoqb#*g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); R= a|Blp
int nCount = input.readInt(); liEPCWl&
nStartPos = new long[nCount]; &vHoRY
nEndPos = new long[nCount]; w|3z;-#Q;
for(int i=0;i<nStartPos.length;i++) L%">iQOG#
{ P<oehw'>
nStartPos = input.readLong(); S(QpM.9*
nEndPos = input.readLong(); :#2Bw]z&z
} w'L\?pI
input.close(); mrTlXXz
} A+HF@Uw}^
catch(IOException e){e.printStackTrace ();} <Q$@r?Mu]
catch(Exception e){e.printStackTrace ();} r[1i*b$
} :WQ^j!9'
ODZ5IO}v
0,r}o
private void processErrorCode(int nErrorCode) tzZ63@cm
{ J5*tJoCYS
System.err.println("Error Code : " + nErrorCode); ckV`OaRw4
} oV)~@0B&0
avjpA?Vz
0WT{,/>
//停止文件下载 hhb?6]Z/
public void siteStop() #btLa\HJ
{ 0fc/wfv<
bStop = true; 0?sRDYaX;c
for(int i=0;i<nStartPos.length;i++) aHlcfh9|
fileSplitterFetch.splitterStop(); nJbtS#`G4
_4TH4~cY
"~`I::'c
} Z.d7U~_
} ekI2icD
//负责部分文件的抓取 A2^\q>_#
**FileSplitterFetch.java jATI&oX
*/ cbeLu'DWB.
package NetFox; #u2J;9P
"-_fv5jL
p/(~IC"!J
import java.io.*; t'9*R7=
import java.net.*; u?>B)PW
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cQG +$0(
public class FileSplitterFetch extends Thread { ?/TSi0R
'iy*^A `Y
0$_oT;{8
String sURL; //File URL YiYV>gaf"H
long nStartPos; //File Snippet Start Position vK(i9>;7
long nEndPos; //File Snippet End Position lW<PoT
int nThreadID; //Thread's ID |4 v0:ETb$
boolean bDownOver = false; //Downing is over qe#P?[
boolean bStop = false; //Stop identical qs|mj}?
FileAccessI fileAccessI = null; //File Access interface rX*H)3F
;g6M%;1-
*eIJwXE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .R)PJc5^
{ x??pBhJH
this.sURL = sURL; ]DZE%
this.nStartPos = nStart; {)DHH:n
this.nEndPos = nEnd; 6Z#\CixG
nThreadID = id; tS|9fBdCs
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9 Yx]=n
} ;WgJ<&33
ub7zA!%
6UevpDB
public void run() df*5,NV'-*
{ h\7fp.
while(nStartPos < nEndPos && !bStop) H(2!1?N+
{ ex+\nD>t4
Wqc)Fv70m
_nD$b={g
try{ FvN<<&B
URL url = new URL(sURL); {D!6%`HKV+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Op"M.]#
httpConnection.setRequestProperty("User-Agent","NetFox"); o8zy^zN$6
String sProperty = "bytes="+nStartPos+"-"; y'(Ne=y
httpConnection.setRequestProperty("RANGE",sProperty); M(RZ/x
Utility.log(sProperty); /D5`
;=geHiQHA
I+Jm>XN
InputStream input = httpConnection.getInputStream(); L,SGT8lL
//logResponseHead(httpConnection); dcLA1sN,
k4,BNJt'Z
?6(I V]
byte[] b = new byte[1024]; UJ0<%^f
int nRead; Dw=gs{8D
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wUiys/OVM
{ 3l[McZ
nStartPos += fileAccessI.write(b,0,nRead); ?notxE7 ]
//if(nThreadID == 1) :[\v
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); baJxU:Y=p
} d}LRl"_n
w$H^q !(
9Q(+ZG=JkV
Utility.log("Thread " + nThreadID + " is over!"); 5K^69mx
bDownOver = true; 7@Zx@
//nPos = fileAccessI.write (b,0,nRead); #mZpeB~
} CqHK%M
catch(Exception e){e.printStackTrace ();} Rp*R:3 C
} ~zil/P8
} ebS0qo[oLH
IP``O!WP
'; =f
//打印回应的头信息 wj[\B*$?
public void logResponseHead(HttpURLConnection con) GiP`dtK
{ [01.\eh
for(int i=1;;i++) '\Jj8oJQj
{ B.g[c97
String header=con.getHeaderFieldKey(i); Ct2j ZqCDo
if(header!=null) #O$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); AX?fuDLs
Utility.log(header+" : "+con.getHeaderField(header)); I8+~ &V}
else [cTe54n
break; %STliJ
} %|^OOU}
} )x}l3\s
*<E]E?
'xhcuVl
public void splitterStop() /" ${$b{
{ G P:FSprP
bStop = true; ?."&MZ
} $U$V?xuE
|+35y_i6
z\0CE]#T
} tp6M=MC%
eh4gQ^l
28/ ADZ
/* mNb ?*3\
**FileAccess.java V$"ujRp
*//文件访问(定位，写) QCH}-q)
package NetFox; `(1K
import java.io.*; JYrY[',u
[q_`X~3
U\veOQ;mW
public class FileAccessI implements Serializable{ PqyA1
UA4J>1 i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B3H|+
RandomAccessFile oSavedFile; /;7y{(o
long nPos; pM{nh00[
Z.W66\8~}^
s[K^9wz
public FileAccessI() throws IOException yz-,)GB6
{ b B x?
this("",0); 4Sm]>%F':
} %r-V2)
p. R2gl1m
B|C/ Rk6?
public FileAccessI(String sName,long nPos) throws IOException Kx.X7R
{ 2:BF[c`
oSavedFile = new RandomAccessFile(sName,"rw"); FuUD 61JHY
this.nPos = nPos; B!dU>0&Ct
oSavedFile.seek(nPos); :9R=]#uD
} Vs)--t
cooUE<a
[6)UhS8
public synchronized int write(byte[] b,int nStart,int nLen) *\wp?s>-t
{ !IC-)C,q
int n = -1; DNR~_3Aq
try{ 1VF
oSavedFile.write(b,nStart,nLen); tV_t6x_.
n = nLen; "F3]X)}
} <W`#gn0b6
catch(IOException e) V~T@6S
{ WpS1a440
e.printStackTrace (); (faK+z,*6R
} %*o8L6Hn
'qArf
+B'8|5tPX
return n; Z<#hS=eY
} 4<lQwV6=
BaO1/zk
Tzt,/e
} [L6w1b,
^9_UUzf\
c(U
/* [w0/\]o
**SiteInfoBean.java Z2Zq'3*
*/ 2[B4f7
package NetFox; [3W*9j
;uqx@sx ;
`:wvh(
public class SiteInfoBean { f`8OM}un&
Q\Gq|e*
9Ew7A(BG_3
private String sSiteURL; //Site's URL B-*E:O0y
private String sFilePath; //Saved File's Path SVa6V}"Iv
private String sFileName; //Saved File's Name FZ|CqD"#
private int nSplitter; //Count of Splited Downloading File yoRU_%xA
N7%TYs
>tG+?Y'{
public SiteInfoBean() ? b[n|^wS
{//nSplitter的缺省值为5 C{Asp
//default value of nSplitter is 5 MlJVeod
this("","","",5); (>=7ng^
} 2/36dGFH
0Rz(|jlbS
j'HkBW:L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2$ !D* <
{ wNNB;n`l
sSiteURL= sURL; yMc:n"-[
sFilePath = sPath; Jz:r7w{4eB
sFileName = sName; Bi~:>X\[^6
this.nSplitter = nSpiltter; PF`rWw
{SZ% Xbo
3L_I[T$s
} TwvAj#j
a=xT(G0Re
pilh@#_h
public String getSSiteURL() EPX8Wwf
{ H@l}[hkP
return sSiteURL; >Z Ke
} S'U@X
zSv^<`X3
tfkr+ /
public void setSSiteURL(String value) a$9A(Pte
{ 6P`)%zj
sSiteURL = value; JI|6B
} DjCx~@
.mL#6P!d3^
U@TjB
public String getSFilePath() -$<O\5cAQ
{ ~|Z'l%<Os
return sFilePath; s?3i)Ymr
} !umEyd@ "
m"-[".-l-
b8BD8~;
public void setSFilePath(String value) wU`!B<,j
{ k_GP>b\"k
sFilePath = value; u-DK_^v4M
} Rt(J/%;
*Q}[ ]g
(LJ@SeM;
public String getSFileName() Gzt=u"FV
{ ;\y;
return sFileName; b!$}ma;B
} kw,$NK'
/.V0ag'G
#\4 b:dv
public void setSFileName(String value) Qu%D
{ uH\kQ9f
sFileName = value; ?mRE'#
} },+~F8B
:Dl%_l
>_X/[<
public int getNSplitter() X1A<$Am1
{ Vf-5&S&9
return nSplitter; Omag)U)IPh
} cs_}&!c{
Zv qn%K],
$T }Tz7(
public void setNSplitter(int nCount) vt]F U<
{ }Ia 0"J4
nSplitter = nCount; 80ZnM%/}
} > %*B`oqo
} %85Icg
)u@c3?$6
rOl6lQW
/* u/AT-er;
**Utility.java |V`S>m%N
*/ Sl~x$9`
package NetFox; =^h~!ovj:
<%bw/
_zC (J
public class Utility { (TSqc5^H
~!+h?[miV
\&A+s4c")
public Utility() w@]jpH;WX
{ 0H=9@
'I/h(
hSqMaX%G
} 2HOe__Ns
M?o{STt
//线程睡眠 9 Aivf+
public static void sleep(int nSecond) "dN< i
{ !Qu PG/=X
try{ `?o=*OS7Y
Thread.sleep(nSecond); H`<?<ak6'M
} sms1%%~
catch(Exception e) 8?jxDW a
{ oL *n>dH
e.printStackTrace (); a0d ,
} \3{3ly~L
} c<qe[iyt/
VEh]p5D
//日志 RR>G]#k
public static void log(String sMsg) N&;\PfG
{ JmWR{du
System.err.println(sMsg); #q4*]qGHm
} =B5E0x
w@N{@tG
C;#"td
public static void log(int sMsg) L:U4N*
{ ^o%_W0_r
System.err.println(sMsg); e)pTC97^L
} Hc!!tbBQ
} ;9rTE|n
lL2-.!]R
l]vohLz 3!
/* fykI,!
**TestMethod.java ` py}99G
*/ d7i#w #
package NetFox; rycJyiw<-
&X w`T9<
%F$N#YG
public class TestMethod { J%r7<y\
d)*(KhYie@
_'*DT=H'U
public TestMethod() 2oNV=b[
{ ///xx/weblogic60b2_win.exe u 2lXd'
try{ +#v4B?NR
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |[wyc!nY).
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <;KRj85"j
SiteFileFetch fileFetch = new SiteFileFetch(bean); u[`v&e
fileFetch.start(); m'.T2e.u
} 4]"w b5%
catch(Exception e){e.printStackTrace ();} fu>Qi)@6a1
Fg@ ACv'@
FuMq|S
} r } 7:#XQ
ib Ue*Z["1
LV=^jsQ5
public static void main(String[] args) -R@JIe_28f
{ ,^+#M{Z
new TestMethod(); M7U:g}
} 1E^{B8cm
} m3%ef
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