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)); zMG4oRPP
} "90}H0(+
for(int i=0;i<nEndPos.length-1;i++) :N[2*.c[
{ .58AXg
nEndPos = nStartPos[i+1]; # I<G:)
} 7'o?'He-.2
nEndPos[nEndPos.length-1] = nFileLength; yrIT4y
} 95+}NJ;r
} #?-W.
#F9$"L1Hg
@-7K~in?^
//启动子线程 T0SD|'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z$pR_dazU
for(int i=0;i<nStartPos.length;i++) /R,/hiKx\
{ x##Iv|$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wm\f:|U5`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ())|x[>JS+
nStartPos,nEndPos,i); oZ=e/\[K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G>!"XK:fB
fileSplitterFetch.start(); J:Qp(s-N^:
} S1=c_!q%9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r|P4|_No
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); dxU[>m;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l p? h~
nEndPos = " + nFileLength); I,#U _
// fileSplitterFetch[nPos.length-1].start(); \"lzmxe0p
JLeV@NO
G%6wk=IH
//等待子线程结束 +FJ o!~1
//int count = 0; a;lCr|*
//是否结束while循环 `=\G>#p<T
boolean breakWhile = false; ({8Q=Gh
9~4Kbmr>q
16]O^R;r
while(!bStop) s$]I@;_
{ YnNei 7R
write_nPos(); xqG` _S l
Utility.sleep(500); (V+(\<M
breakWhile = true; w S;(u[W
|{_%YM($
5]F9o9]T
for(int i=0;i<nStartPos.length;i++) ?hwQY}
{ #AY+[+
if(!fileSplitterFetch.bDownOver) kTnvD|3_!P
{ -&HN h\
breakWhile = false; ;lK2]
break; 2f-Z\3)9 J
} GRs;-Jt
} l"vT@g|
if(breakWhile) foN;Q1?lS
break; 't>Qj7vh0
iCc\p2p
Onk~1ks:
//count++; NyGF57v[M
//if(count>4) bLUn0)c
// siteStop(); hMDyE.X-
} D_8hn3FH
Jv7M[SJ#x
|Rl|Th
System.err.println("文件下载结束！"); u!X2ju<
} mq "p"iI
catch(Exception e){e.printStackTrace ();} A#p@`|H#B
} 1%+0OmV&
Llzowlfe
co12\,aD
//获得文件长度 69L s"e
public long getFileSize() QKF2_Acc
{ CBvBBt*
int nFileLength = -1; LyQO_mT2
try{ rDSt ~l
URL url = new URL(siteInfoBean.getSSiteURL()); 0xjV*0?s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2R_k$kHl
httpConnection.setRequestProperty("User-Agent","NetFox"); TS%cTh'ItH
hgh1G7A&
0zfrx-'zN
int responseCode=httpConnection.getResponseCode(); pjoI};
if(responseCode>=400) )zt5`"/o
{ x^;nfqn|
processErrorCode(responseCode); HnpGPGz@F
return -2; //-2 represent access is error {UhZ\qe
} Q/+a{m0f
w"Z>F]YZ
Uligr_c?
String sHeader; lmd0Q(I
d,H%
\mycn/e
for(int i=1;;i++) ]-q:Z4rb
{ Isi,Tl ^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z-~^)lo
//Utility.log(in.readLine()); : Z.mM5
sHeader=httpConnection.getHeaderFieldKey(i); aRV!0?fS
if(sHeader!=null) Psv-y
{ )/=J=xw2
if(sHeader.equals("Content-Length")) Pgo5&SQb
{ PJ_|=bn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rXaL1`t*
break; P_Zo}.{
} h(zi$V
} X31kHK5F_
else "y`?KY$[N
break; Wqqo8Y~fq
} %Wc-.ER
} =GpLlJ`-
catch(IOException e){e.printStackTrace ();} PK~okz4b
catch(Exception e){e.printStackTrace ();} ]A\n>Z!;
K;Xn!:) V:
%?g]{
Utility.log(nFileLength); {7;TQ?/
|;].~7^
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return nFileLength; 44]ae~@a
} ^a]i&o[c
{wm `
DnTM#i:
//保存下载信息（文件指针位置） [C&c;YNp
private void write_nPos() $X{& KLM[
{ [R~HhM
try{ IEA[]eik>
output = new DataOutputStream(new FileOutputStream(tmpFile)); h0gT/x
output.writeInt(nStartPos.length); EuAa
for(int i=0;i<nStartPos.length;i++) g5?Fo%W
{ <&NR3^Eq
// output.writeLong(nPos); XYn$yR\dj
output.writeLong(fileSplitterFetch.nStartPos); gf!j|O;
output.writeLong(fileSplitterFetch.nEndPos); K[9<a>D`
} {<i!Pm
output.close(); }Jc^p
} *7Mrng
catch(IOException e){e.printStackTrace ();} II2oV}7?
catch(Exception e){e.printStackTrace ();} (O&b:D/Y
} ;uJVY)7a
x_Z~k
6ZM<M7(V
//读取保存的下载信息（文件指针位置） qR1ez-#K
private void read_nPos() q}8R>`Z{
{ W}e5 4-lu
try{ `j2z=5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,p2 Di
int nCount = input.readInt(); duM>(y
nStartPos = new long[nCount]; M\GS&K$lq
nEndPos = new long[nCount]; $pD^O!I)?
for(int i=0;i<nStartPos.length;i++) FYi<+]HZ
{ q80?C.,`
nStartPos = input.readLong(); ;CC[>
nEndPos = input.readLong(); 8?(4E 'vf
} Zs4N0N{
input.close(); =l\D7s
} fL@[B{XMM
catch(IOException e){e.printStackTrace ();} 4ASc`w*0
catch(Exception e){e.printStackTrace ();} ik]UzB
} 5n"'M&Ce
-V+fQGZe
;<*VwXJR
private void processErrorCode(int nErrorCode) aH~il!K
{ -}>Q0d)
System.err.println("Error Code : " + nErrorCode); Z2ZS5a
} O[m+5+
fu|I(^NV
e]5QqM7
//停止文件下载 dW=]|t&
public void siteStop() %>s y`c
{ aR3W9
bStop = true; N@) D,~
for(int i=0;i<nStartPos.length;i++) ei"FN3Rm
fileSplitterFetch.splitterStop(); 1b't"i M
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a7CJ~8-1K
} ^o{O5&i]
} :xA'X+d/'
//负责部分文件的抓取 PeG8_X}u9
**FileSplitterFetch.java cL}g7D
*/ {:"bX~<^
package NetFox; Kg%_e9nj#
tV T(!&(
_ '}UNIL
import java.io.*; ~+1t17
import java.net.*; J4JKAv~3
Y`_6Ny="
-PX {W)Aw
public class FileSplitterFetch extends Thread { EBn7waBS
=A,i9Z&
_E1:3N|
String sURL; //File URL .|rpj&>g
long nStartPos; //File Snippet Start Position LsLsSV
long nEndPos; //File Snippet End Position jKtbGVZ7r
int nThreadID; //Thread's ID ^y??pp<1J
boolean bDownOver = false; //Downing is over 5ecqJ
boolean bStop = false; //Stop identical uh GL1{
FileAccessI fileAccessI = null; //File Access interface Vdjca:`
f6z[k_lLN
Bp b_y;E
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException sqkPC_;A
{ K/08F|]a
this.sURL = sURL; toP7b
this.nStartPos = nStart; V43|Ej}E
this.nEndPos = nEnd; u6D>^qF}@'
nThreadID = id; VbZZ=q=Kd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :*\JJ w
} ?{+}gS^
1_F2{n:yp
x&kF;UC
public void run() fghJj@ES
{ n0cqM}P@;!
while(nStartPos < nEndPos && !bStop) >`t |a
{ [aIQ/&Y
05w_/l+
O* 7"Q&
try{ -()CgtSR
URL url = new URL(sURL); 7H=/FT?e]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z;Kyg}
httpConnection.setRequestProperty("User-Agent","NetFox"); d^,u"Z9P
String sProperty = "bytes="+nStartPos+"-"; _RAPXU~ 6-
httpConnection.setRequestProperty("RANGE",sProperty); b2ZKhS8
Utility.log(sProperty); VRT| OUq
[t>}M6?R:
4Sw)IU~K(
InputStream input = httpConnection.getInputStream(); .)Du ;
//logResponseHead(httpConnection); &'i>5Y
6)Kg!.n%f
/9i2@#J}W1
byte[] b = new byte[1024]; 38rC; 6
int nRead; ?*Jv&f#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N 0`)WLW
{ 2'N%KKmJL
nStartPos += fileAccessI.write(b,0,nRead); B1\}'g8%f
//if(nThreadID == 1) g"F vD_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IY+P Yad
} -cOLgrmp
A5z5e# ,u
N U\B
Utility.log("Thread " + nThreadID + " is over!"); rZ *}jD[
bDownOver = true; !hEtUF
//nPos = fileAccessI.write (b,0,nRead); l+RBe<Mq
} (rvK@
catch(Exception e){e.printStackTrace ();} +1_NB;,e
} "*<9)vQ6|
} s<aJ pi{n4
j^>J*gLM}W
^Qq_|{vynf
//打印回应的头信息 IL&Mf9m
public void logResponseHead(HttpURLConnection con) *ewE{$UpK
{ 4OC^IS
for(int i=1;;i++) jsjH.O
{ L_Ff*
String header=con.getHeaderFieldKey(i); bF<FX_}!s!
if(header!=null) 8|HuxE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }H\wed]F/
Utility.log(header+" : "+con.getHeaderField(header)); M2{{B^*$6
else ' FF@I^O
break; )}tI8
} oBpHmMzA
} 4Y;z46yM%
,A4v|]kq]
'0lX;z1
public void splitterStop() j0>Q:hn
{ r_F\]68
bStop = true; o^}K]ML!t
} :!n_a*.{
B!4chxzUZ
]-&A)M6
} V+(1U|@~
!0i
"@#^/m)
/* Rq|7$O5
**FileAccess.java >;LXy
*//文件访问(定位，写) M2l0x @|
package NetFox; i]Njn k
import java.io.*; scT,yNV
$qV, z
&gR)Y3
public class FileAccessI implements Serializable{ J>y}kzCz
)[oegfnn-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 N2#Wyt8MC
RandomAccessFile oSavedFile; 5<^$9('
long nPos; C8W#$a
2<q>]G-nN
=^\yE"a
public FileAccessI() throws IOException 3"FvYv{
{ }>]V_}h
this("",0); P%2aOsD0
} m<}>'DT
6#hDj_(,
IOhJL'r
public FileAccessI(String sName,long nPos) throws IOException UuPXo66F]
{ L7VDZCV
oSavedFile = new RandomAccessFile(sName,"rw"); $KHw=<:)/
this.nPos = nPos; >"5f B
oSavedFile.seek(nPos); qQ6rF nA
} ?71?Vd
l!qhK'']V"
@cRR
public synchronized int write(byte[] b,int nStart,int nLen) lY -2e>
{ H{hd1
int n = -1; $lVR6|n
try{ W T~UEK'
oSavedFile.write(b,nStart,nLen); 79`OB##
n = nLen; 1 etl:gcEC
} ![1+=F!
catch(IOException e) 'o}v{f
{ P|j|0o,8p
e.printStackTrace (); Cw$0XyO
} n/9.;9b$I
1*U)\vK~
E.LD1Pm0
return n; aG_@--=
} EmG':K(
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X} {z7[
} -+ylJo[D
C-h9_<AwJQ
;YN`E
/* ] MP*5U>;
**SiteInfoBean.java .,h>2;f
*/ f.)z_RyGd
package NetFox; Jt++3]
aW=c.Q.
@I"&k!e<2
public class SiteInfoBean { 0{Uc/
Eqizx~eqq
pKZRgA#kN
private String sSiteURL; //Site's URL RW-)({
private String sFilePath; //Saved File's Path 05>mRqVL
private String sFileName; //Saved File's Name YN]xI
private int nSplitter; //Count of Splited Downloading File $;iMo/
c!0u,6
+}VaQ8ti4
public SiteInfoBean() OCW0$V6;D-
{//nSplitter的缺省值为5 S@Iza9\|@
//default value of nSplitter is 5 A>\5fO
this("","","",5); 4t 5i9+h
} |VX )S!
p~'iK4[&6
>V%lA3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6;:z?Q
{ \1Xr4H u
sSiteURL= sURL; Yyxsj9
sFilePath = sPath; Xfc+0$U@
sFileName = sName; !\< [}2}
this.nSplitter = nSpiltter; ^/~ZP?%]
dvAG}<
0 i'bo*
} dl]pdg<
Y5{KtW
&2,3R}B/
public String getSSiteURL() .}9Lj
{ ^r=Wj@`
return sSiteURL; @>fsg-|
} *"nN To
'\O[j*h^.
lfw|Q@
public void setSSiteURL(String value) dzQs7D}
{ x{O) n
sSiteURL = value; ]4ib^R~Z
} : E`78
38GkV.e}$
m]+~F_/
public String getSFilePath() K'Y/0:"*
{ Uiv4'vYg
return sFilePath; 5,\-;
} q4#$ca[_ak
5rb<u>e{
R$ra=sL`
public void setSFilePath(String value) S,Z~-j
{ |*/-~5"
sFilePath = value; ?6Wv["%
} q4ttmL8
R-Ys<;
Q7.jSL6
public String getSFileName() 2YDD`:R
{ x2,;ar\D
return sFileName; Cnr=1E=
} vM'!WVs
6:~<L!`&
Sse%~:FL
public void setSFileName(String value) ExhK\J
{ g`z;:ao
sFileName = value; E~@&&dU8
} '7Mz]@
sYhHh$mwA
GbC@ |
public int getNSplitter() BG6.,'~7o
{ -5oYGLS$y3
return nSplitter; c,^W/:CQAB
} *knN?`(x
CNe(]HIOH
l 88n*O
public void setNSplitter(int nCount) p()q)P
{ H_ a##z
nSplitter = nCount; M"Af_Pbx
} u6 QW*8b4
} -9~$Ll+2h
>V?W_oM)
^F'~|zc"C
/* H:EK&$sU
**Utility.java w&@zJ[
*/ xM=ydRu
package NetFox; 6oa>\PDy
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2Wg:eh
public class Utility { <BIQc,)2}
;m7~!m)
?0'e_s
public Utility() rd>>=~vx=/
{ \2!.
k`#E#1niN
|$;4/cKfy
} w/^_w5
b*W,8HF4,
//线程睡眠 F Uz1P
public static void sleep(int nSecond) nuDu
{ <ne?;P1L
try{ CA1Jjm=
Thread.sleep(nSecond); S}fQis
} !?R#e`}
catch(Exception e) 4X",:B}
{ ])G|U A.
e.printStackTrace (); qzNXz_#+u
} ySI}Nm>&=
} A;5_/ 2
Hs$HeAp;
//日志 15VvZ![$V
public static void log(String sMsg) _u""v
{ ,na}' A@a`
System.err.println(sMsg); yN)(MmX'1
} 2}7_Y6RS*
_k :BY
fs yVu|G
public static void log(int sMsg) w_V A:]j4
{ s$zm)y5
System.err.println(sMsg); Y4w]jIv
} giH#t< )W
} \crh`~?>
[NJ2rQ/w7
IhBQ1,&J
/* sPb}A$'
**TestMethod.java bHcBjk.\
*/ 1;KJUf[N
package NetFox; $0x+b!_l@
*P5\T4!+d
O8A(OfX
public class TestMethod { tK@7t0
V;g) P
-+u}u=z%
public TestMethod() =>lX brJ
{ ///xx/weblogic60b2_win.exe |Xm$O1Wa
try{ S,C c0)j>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o=#ym4hJ%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]%I\FefT
SiteFileFetch fileFetch = new SiteFileFetch(bean); #>HY+ ;
fileFetch.start(); ~ o2Z5,H
} *iY:R
catch(Exception e){e.printStackTrace ();} 8(&6*-7=
yY!)2{F+
j!kJ@lbP
} zR'EQ
0'THL%lK
<KK.f9^o(
public static void main(String[] args) x_I*6?
{ #_x5-?3
new TestMethod(); 3UmkFK<
} "wcw`TsK
} 3s|:7
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