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)); |}^BF%8V:
} e:kd0)9
for(int i=0;i<nEndPos.length-1;i++) OXCf
{ _vgFcE~E@
nEndPos = nStartPos[i+1]; %q)*8
} g6Nw].{
nEndPos[nEndPos.length-1] = nFileLength; .cA'6J"Bm\
} :bV1M5
} DQRr(r~2Kj
>xJh!w<pB
w,v~
//启动子线程 etkKVr;Kv
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +1Ua`3dWN_
for(int i=0;i<nStartPos.length;i++) pXv@QD#!
{ t (>}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'k(aZ"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), XDcA&cM}p
nStartPos,nEndPos,i); EAi!"NJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tWN hFQ'
fileSplitterFetch.start(); Eggdj+
} wEJ) h1=)^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s`Z'5J;S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8O0E;6b
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", A,'JmF$d
nEndPos = " + nFileLength); B>"O~ gZ{#
// fileSplitterFetch[nPos.length-1].start(); 1hnw+T<<W
xU_Dg56z'&
3iC$ "9!p
//等待子线程结束 I? o)X!
//int count = 0; (#`1[n+b`x
//是否结束while循环 v?en-,{A
boolean breakWhile = false; #\X="'/
Yl!~w:O!o
+IpC
while(!bStop) xesZ7{ o
{ G(6MLh1
write_nPos(); )r^)e4UI
Utility.sleep(500); 3 2MdDa
breakWhile = true; Fv(1A_~IS
vq&u19iP
rp^Gk
for(int i=0;i<nStartPos.length;i++) <>tQa5;
{ \uTy\KA
if(!fileSplitterFetch.bDownOver) !?u{2D
{ ~gAp`Q
breakWhile = false; ;mw$(ZKa#
break; _K5R?"H0
} <5wk~|@t
} <B%s9Zy
if(breakWhile) V<%eWT)x7C
break; 9;*-y$@
&>]c"?C*
V`/D!8>
//count++; FhkS"y
//if(count>4) eVy>
// siteStop(); $x'p+&n\
} +>uiI4g
-lNq.pp3-$
6bXR?0$*M.
System.err.println("文件下载结束！"); WzwH;!
} [~[)C]-=
catch(Exception e){e.printStackTrace ();} RZg8y+jM
} 5!pof\/a
$V0G[!4
Bl"BmUn
//获得文件长度 =KctAR;
public long getFileSize() ra4$/@3n
{ 7\?0d!
int nFileLength = -1; iE;D_m.>`O
try{ !8V
URL url = new URL(siteInfoBean.getSSiteURL()); yK3b^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -~'{WSJ
httpConnection.setRequestProperty("User-Agent","NetFox"); ZgP~VB0)$
1'G&PX
n8dJ6"L<"
int responseCode=httpConnection.getResponseCode(); qij<XNZU"&
if(responseCode>=400) I\DH
{ XFiP8aX<
processErrorCode(responseCode); &=-ZNWNo
return -2; //-2 represent access is error ev}ugRxt|k
} &eqeQD6
*49lM;
vTdJe
String sHeader; hN3*]s;/6z
6(5YvT
knsTy0]
for(int i=1;;i++) c :{#H9
{ 4N- T=Ig
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =>kE`"{!
//Utility.log(in.readLine()); V4.&"0\n#
sHeader=httpConnection.getHeaderFieldKey(i); G'M;]R9EP
if(sHeader!=null) K#e&yY
{ k+D"LA%J
if(sHeader.equals("Content-Length")) _,?<r&>v6
{ KT>eE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); oN\IQ7oI
break; +[R,wsG
} ,@#))2<RK
} DNGXp5I
else +p Y*BP+~i
break; |*T3TsP u
} ~g|Z6-?4Jj
} RiPxz=kr
catch(IOException e){e.printStackTrace ();} !)1gGXRY
catch(Exception e){e.printStackTrace ();} /YLHg5n8+
R|&Rq(ow"
Sz_{#-
Utility.log(nFileLength); Z?);^m|T
QQPT=_P]
Mkj`
return nFileLength; 9[5qN!P;y
} jgW-&nK!
iaAj|:
IOjp'6Yr
//保存下载信息（文件指针位置） iiw\
private void write_nPos() y$Rr,]L
{ VPh0{(O^=
try{ /~O>He
output = new DataOutputStream(new FileOutputStream(tmpFile)); j^Vr!y
output.writeInt(nStartPos.length); 6VsgZ"Il
for(int i=0;i<nStartPos.length;i++) x/B1\U I
{ UK7pQt}9
// output.writeLong(nPos); :"~SKJm
output.writeLong(fileSplitterFetch.nStartPos); S /kM#
output.writeLong(fileSplitterFetch.nEndPos); 4*D'zJsJ
} $\w<.)"#
output.close(); <Pm!#)-g9
} b:M1P&R
catch(IOException e){e.printStackTrace ();} /Z?$!u4I
catch(Exception e){e.printStackTrace ();} Bo#,)%80
} &qjc+-r{l
1z6$>{FUR
wOLDHg_
//读取保存的下载信息（文件指针位置） jGSY$nt9
private void read_nPos() ieL7jN,'m
{ !<8-juY
try{ T@4R|P&{)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?^Q8#Y^M
int nCount = input.readInt(); 2d#3LnO
nStartPos = new long[nCount]; Q:5^K
nEndPos = new long[nCount]; 4!</JZX~$
for(int i=0;i<nStartPos.length;i++) bih%hqny
{ +QZ}c@'r
nStartPos = input.readLong(); N*w6D:
nEndPos = input.readLong(); nr{#Krkb
} @CTSvTt$
input.close(); u{'|/g&
} ].Sz2vI
catch(IOException e){e.printStackTrace ();} Z0'&@P$
catch(Exception e){e.printStackTrace ();} 44x+2@&1
} =.48^$LWx
\x7^ly$_
h]>QGX[kC
private void processErrorCode(int nErrorCode) CQANex4&\
{ $SOFq+-T
System.err.println("Error Code : " + nErrorCode); L7`=ec<
} =] +owl2
m}$7d5
E^`-:L(_
//停止文件下载 w!eY)p<
public void siteStop() {M^BY,%*
{ [KMNMg
bStop = true; */6lyODf
for(int i=0;i<nStartPos.length;i++) TFAd
fileSplitterFetch.splitterStop(); +e87/\5
4aGVIQ
$VxKv7:
} nf0]<x2
} \V_Tc`
//负责部分文件的抓取 VrIR!9%:
**FileSplitterFetch.java r6QshCA"
*/ Ht"?ajW{
package NetFox; B{lj.S`mB
Bc*FH>E
&|K9qa~)Y
import java.io.*; *yZ `aKfH
import java.net.*; {zTnE?(o`
YZk.{#^c
XkhGU?={
public class FileSplitterFetch extends Thread { 67g"8R#.V
FX1H2N(
EvKzpxCh
String sURL; //File URL X=KC+1e
long nStartPos; //File Snippet Start Position W8_$]}G8E
long nEndPos; //File Snippet End Position idNra#
int nThreadID; //Thread's ID Rz#q68
boolean bDownOver = false; //Downing is over ^?8/9o
boolean bStop = false; //Stop identical ;EB^1*AEw
FileAccessI fileAccessI = null; //File Access interface `oU|U!|
/& W&
0NF=7 j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ZYS]Et[Q
{ |JLXgwML
this.sURL = sURL; oMNSQMlI
this.nStartPos = nStart; NXCvS0/h
this.nEndPos = nEnd; ='t}d>l
nThreadID = id; {[)n<.n[g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vB%os Qm
} gkmV;0
1N}vz(0"
)`BKEaf
public void run() p/U{*i]t
{ 4:9N]1JCb
while(nStartPos < nEndPos && !bStop) mIZ6[ ?
{ :2.<JUDM
jx{wOb~oO)
z*UgRLKZD
try{ Y:R*AOx
URL url = new URL(sURL); ni85Ne$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =<%[P9y
httpConnection.setRequestProperty("User-Agent","NetFox"); 4nrn Npf`b
String sProperty = "bytes="+nStartPos+"-"; EO`eg]
httpConnection.setRequestProperty("RANGE",sProperty); ?2%;VKN4
Utility.log(sProperty); aD+4uGN
wJZuJ(
q5G`q&O5
InputStream input = httpConnection.getInputStream(); {e5DQ21.
//logResponseHead(httpConnection); v`@NwH<r
/Nkxb&
*M^<oG
byte[] b = new byte[1024]; 5P{[8PZxbV
int nRead; cLf<YF
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,M9e *
{ bq2f?uD-}
nStartPos += fileAccessI.write(b,0,nRead); v5F+@ug
//if(nThreadID == 1) :8`~dj.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3rY\y+m
} y_'6bpb
U=WS]
x5|^p=
Utility.log("Thread " + nThreadID + " is over!"); 3 "iBcsLn
bDownOver = true; "AP$)xM-:
//nPos = fileAccessI.write (b,0,nRead); )Dp0swJ
} CTS1."kx1
catch(Exception e){e.printStackTrace ();} q BIekQT
} \n`/?\r.z
} PthgxB^
4.p:$/GTS
+e,c'.
//打印回应的头信息 \zcR75
public void logResponseHead(HttpURLConnection con) UM/!dt}DnF
{ 6e8 gFQ"w2
for(int i=1;;i++) .DI?-=p|_#
{ osl\j]U8
String header=con.getHeaderFieldKey(i); 2qot(Zs1i
if(header!=null) K3Bw3j 9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d'"|Qg_'
Utility.log(header+" : "+con.getHeaderField(header)); wX5q=I
else d N$,AOT
break; !S%0#d2
} 1F_$[iIX]
} ('{aOiSH
_, E/HAX
Cs(sar:7
public void splitterStop() >(-A"jf
{ *4e?y
bStop = true; \1SC:gN*#
} ]}kw'&
ap8q`a{j^
4l7 Ny\J
} zn>+\
d@p#{ -
ZS%W/.?
/* ;{aGEOP'U
**FileAccess.java :}yT?LIyP
*//文件访问(定位，写) Af\
package NetFox; Vm[F~2+HX
import java.io.*; 1Au+X3
Xo:Mar
hbg$u$1`,
public class FileAccessI implements Serializable{ /wax5FS'I,
KZTLIZxI-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OLqV#i[K#9
RandomAccessFile oSavedFile; u>]3?ty`
long nPos; jo^c>ur
n\M8>9c
Y!8FW|
public FileAccessI() throws IOException ="5D}%
{ c6lCF &
this("",0); [_nOo`
} @TQ/Z$y
F}7sb#G
@gfW*PNjlP
public FileAccessI(String sName,long nPos) throws IOException lKB9n}P
{ l^d'8n
oSavedFile = new RandomAccessFile(sName,"rw"); >[Wjzg
this.nPos = nPos; 0k{\W
oSavedFile.seek(nPos); b"Q8[k |d
} YVwpqOE.=
Xl<iR]lda
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public synchronized int write(byte[] b,int nStart,int nLen) 3C<G8*4);/
{ BM/o7%]n
int n = -1; l=b!O
try{ K"x_=^,Yu*
oSavedFile.write(b,nStart,nLen); [@ev%x,
n = nLen; 8>t,n,k
} ,0a_ou"P=_
catch(IOException e) swxX3GR
{ 2QRO$NieV
e.printStackTrace (); 8}m J)9<7
} p<{P#?4 g
tsJR:~
M2-`p
return n; SAdE9L =d
} ^?Mp(o
@lF?+/=$
t^KQ*8clG
} Ku%tM7ad
Ny^f'tsA
}%8ZN :
/* FGx)?
**SiteInfoBean.java p<=Lh47 =
*/ mf3,V|>[\
package NetFox; &hO-6(^I
BLyV~
ewU*5|*[
public class SiteInfoBean { 6{buel(|e
?UAuUFueA
fwv^dEe
private String sSiteURL; //Site's URL $j.;$~F
private String sFilePath; //Saved File's Path 88~Nrl=co
private String sFileName; //Saved File's Name -n&&d8G^s
private int nSplitter; //Count of Splited Downloading File $C;i}q#
-0d9,,c
*,4rYb7I w
public SiteInfoBean() 7h}gIm7e"
{//nSplitter的缺省值为5 q* p
//default value of nSplitter is 5 (|K+1R
this("","","",5); "-$}GUK?Z
} Jg;[k
1~c\J0h)d
P|<V0 Vs.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~^1y(-cw
{ 0[l}@K?
sSiteURL= sURL; 'z;(Y*jb
sFilePath = sPath; =G:Krc8w@
sFileName = sName; lH4Nbluc^
this.nSplitter = nSpiltter; EwzR4,r\M
R^.PKT2E
BA c+T
} TRGpE9i
ksv]
S&`6pN
public String getSSiteURL() |reA`&<q
{ ^YLC{V
return sSiteURL; u2oS Ci
} [f_^BU&
<a"(B*bBd
$pES>>P
public void setSSiteURL(String value) _ p\L,No
{ Wk0E7Pr
sSiteURL = value; ']1n?K=A
} mH$tG $
['IH*gi
KV_/fa~Ry
public String getSFilePath() ^aSb~lce
{ irAXXg
return sFilePath; cW:y^(Xii
} =\O#F88ui
% "(&a'B
Me.I>7c
public void setSFilePath(String value) lcdhOjz!N
{ ^O_Z5NbC3
sFilePath = value; M@cFcykK
} Te-p0x?G.
[7vV#s3kJ
G,)zn9X
public String getSFileName() RsZj
{ cqG6di7#
return sFileName; EV?}oh"x
} H>CbMz1u
O-(V`BZe
7_I83$p'
public void setSFileName(String value) l8oaDL\f
{ [Z$H<m{c-
sFileName = value; B7 s{yb
} WQ9e~D"
fQfn7FaW_\
VE+H! ob A
public int getNSplitter() e$~[\ w
{ wo@ T@Ve~
return nSplitter; OD8 fn
} aFTWzz
QF>T)1&J[7
&*v\t\]
public void setNSplitter(int nCount) &en. m>9,
{ O&l4/RtQ\)
nSplitter = nCount; TDH^x1P
} ~7 i{~<?
} JIySe:p3
^ }7O|Y7
A8m06
/* f!'i5I]
**Utility.java fp [gKRSF
*/ 4'O,xC
package NetFox; ?9~^QRLT
?\o~P
Xq135/d
public class Utility { cwmS4^zt8
~XOmxz0
v #+ECx
public Utility() tAv3+
{ I\mF dE
QC+ Z6WS;
/JR+WmO
} 5NhFjPETr
hN3FH#YO
//线程睡眠 Y^+x<
public static void sleep(int nSecond) (Q8!5s
{ Q4u.v,sE
try{ &e^;;<*w
Thread.sleep(nSecond); `s7pM
} 0ID9=:J
catch(Exception e) \FsA-W\X
{ 8US#SI'x
e.printStackTrace (); #gC[L=01
} Dj\nsc@e3
} yNI0Do 2
`Z;Z^c
//日志 k6bct@7
public static void log(String sMsg) \bARp z?a
{ l'"nU6B&
System.err.println(sMsg); Blxa0&3
} z=>fBb>w7
a}yb~:TC
gv`_+E{P
public static void log(int sMsg) *V2;ds.~
{ Q a (Sb
System.err.println(sMsg); z8X7Y >+SA
} a`'>VCg
} |]< 3cW+
YmC}q20;
z x-[@G
/* ]d1'5F][H
**TestMethod.java -qP)L;n
*/ uyYV_Q0~;
package NetFox; Q4cCg7|0
;oOTL'Vu
YZf{."Opj[
public class TestMethod { XM:BMd|
vFk@
u !BU^@P
public TestMethod() 1 m'.wh|
{ ///xx/weblogic60b2_win.exe hi"C<b.
try{ 0Q{lyu
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,?8a3%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TQ(q[:>
SiteFileFetch fileFetch = new SiteFileFetch(bean); %tVU Rj
fileFetch.start(); (,I:m[0
} 21v--wZ
catch(Exception e){e.printStackTrace ();} 4!/QB6
?,$:~O*w
d~<$J9%
} ;KQU% k$
S(PV*e8
J@-'IJ
public static void main(String[] args) )]fiyXA
{ -YQh F;/
new TestMethod(); b\"F6TF:
} 6:2*<
} "pO
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