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)); PJwEA
} .HDebi
for(int i=0;i<nEndPos.length-1;i++) a(Sv,@/
{ d<Dn9,G
nEndPos = nStartPos[i+1]; Lw*1 .~
} .HOY q
nEndPos[nEndPos.length-1] = nFileLength; BD4"pcr
} MgP{W=h2
} 0~i qG
e[p^p!a
W9jNUZVXE#
//启动子线程 ORtg>az\%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =F[lg?g
for(int i=0;i<nStartPos.length;i++) R`3x=q
{ JJNmpUJ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [J:zE&aj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !G>(j
nStartPos,nEndPos,i); Zih5/I
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5F03y`@ u
fileSplitterFetch.start(); ZpTi:3>
} 3Pa3f >}-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ])68wqD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9dw0<qw1%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?:JdRnH\
nEndPos = " + nFileLength); :7k`R62{
// fileSplitterFetch[nPos.length-1].start(); jQ^Yj"6
:%>oe> _"
KMe.i'
//等待子线程结束 , Z4p0M
//int count = 0; Nq U9/
//是否结束while循环 6BHPzv+Y
boolean breakWhile = false; S#hu2\9D,
gm}C\q9
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while(!bStop) %N1T{
{ iUpSN0XkMM
write_nPos(); KwQXA'
Utility.sleep(500); |oFI[PE
breakWhile = true; O{*GW0}55
6|i`@|#
d)9PEtI
for(int i=0;i<nStartPos.length;i++) v(k*A:
{ ~|qXtds$
if(!fileSplitterFetch.bDownOver) Do(PdF6A
{ 'H FwP\HX
breakWhile = false; ;7)OSGR
break; AV9:O{
} P)4x
} $<14JEU
if(breakWhile) XuA0.b%
break; e ^-3etx
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^Y#@$c
//count++; A>[hC{
//if(count>4) '%3u%;"
// siteStop(); S]tkz*w0*
} `7F@6n
I"~xDa!
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System.err.println("文件下载结束！"); zmdWVFVv
} 7d%A1}Bq$
catch(Exception e){e.printStackTrace ();} rn[$x(G
} ,WzG.3^m
JIB?dIN 1
qW+=g]x\
//获得文件长度 HarYV :
public long getFileSize() '"'D.,[W2
{ (xjqB{U
int nFileLength = -1; 6j?FRs
try{ Ixyvn#ux)
URL url = new URL(siteInfoBean.getSSiteURL()); Bd/} %4V\@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i=x.tsJ:hB
httpConnection.setRequestProperty("User-Agent","NetFox"); VM=hQYe
{_?T:`
{c&qB`y<.
int responseCode=httpConnection.getResponseCode(); PjiNu.>2(
if(responseCode>=400) dw'<"+zO
{ 6sO
processErrorCode(responseCode); @Pd) %'s
return -2; //-2 represent access is error .ou!g&xu
} ab8oMi`z
H^]Nmd8Q)
hg$qbeUl
String sHeader; ecM4]U
+R3\cRM
3(cU)
for(int i=1;;i++) <W=~UUsn
{ K'a#Mg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'Wo?%n
//Utility.log(in.readLine()); *1 n;p)K
sHeader=httpConnection.getHeaderFieldKey(i); VyB\]EBu
if(sHeader!=null) -G(3Y2
{ 4Z<]4:o
if(sHeader.equals("Content-Length")) Kx(76_XD
{ z" b/osV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %AzPAWcN
break; PU,6h}
} H={O13
} 6M O|s1zk
else .rt8]%
break; 7F>gj
} 0BbiQXU
} !$%/ rQ9
catch(IOException e){e.printStackTrace ();} vB&F_"/X2
catch(Exception e){e.printStackTrace ();} >C*?17\
`@VM<av
)x_W&*oZ
Utility.log(nFileLength); HPu/. oE
krEH`f
Jdk3) \
return nFileLength; Zj%B7s1A
} l044c,AW(
?.4yg(
Fi,e}j=2f
//保存下载信息（文件指针位置） =!1-AR%.^
private void write_nPos() v#FJ+
{ {ar5c&<
try{ &KOG[tv
output = new DataOutputStream(new FileOutputStream(tmpFile)); y^EF<<\
output.writeInt(nStartPos.length); 1]D/3!
for(int i=0;i<nStartPos.length;i++) j]@x Q,y
{ INN/VDsJ
// output.writeLong(nPos); -D&.)N9ctQ
output.writeLong(fileSplitterFetch.nStartPos); CS^ oiV%{s
output.writeLong(fileSplitterFetch.nEndPos); glOqft&>`
} }mtC6G41Q
output.close(); [[/ }1%
} wHBHkz
catch(IOException e){e.printStackTrace ();} (`q6G d
catch(Exception e){e.printStackTrace ();} uMiD*6,$<
} _rWM]
c5T~0'n
{UV<=R,E
//读取保存的下载信息（文件指针位置） Lic{'w&
private void read_nPos() CYTuj>Ww
{ !:g>CDA
try{ Y:tW]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); s/W!6JX4
int nCount = input.readInt(); YYZs#_
nStartPos = new long[nCount]; EyKkjEXx_
nEndPos = new long[nCount]; 6ywnyh
for(int i=0;i<nStartPos.length;i++) onWYT}c{
{ ^5FJ}MMJf
nStartPos = input.readLong(); ,Do$`yO+
nEndPos = input.readLong(); 2m)kyQ
} \ pe[V~F
input.close(); 36x5q 1
} BM=V,BZy
catch(IOException e){e.printStackTrace ();} P0`>{!r6@
catch(Exception e){e.printStackTrace ();} QXIbFv
} )DklOEO
X1 0"G~0
I9Edw]
private void processErrorCode(int nErrorCode) FJn~ =hA
{ Sug~FV?k$e
System.err.println("Error Code : " + nErrorCode); do?S,'(g
} (:j+[3Ht
+_-)0[+p
u$Pf.#
//停止文件下载 f<s'prF
public void siteStop() 0%qctZy
{ YP .%CD(K
bStop = true; 3u"J4%zg|L
for(int i=0;i<nStartPos.length;i++) \ eyQo>(
fileSplitterFetch.splitterStop(); NXWIE4T>*^
#Tg|aW$(*
V!kQuQJ>
} 6>LQGO
} Chb4VoE
//负责部分文件的抓取 D@lAT#vA
**FileSplitterFetch.java npG+#z
*/ ]'1N_m]?
package NetFox; n{qw]/
9>.<+b(>!'
9`gGsC
import java.io.*; !7,K9/"
import java.net.*; $Kw"5cm
%DND&0`
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public class FileSplitterFetch extends Thread { X"qbB4(I
!5' 8a5
I")"s
String sURL; //File URL gqHH Hh
long nStartPos; //File Snippet Start Position &]"_pc/>m
long nEndPos; //File Snippet End Position =aCIaL&9Y
int nThreadID; //Thread's ID eqUn8<<s
boolean bDownOver = false; //Downing is over Z>MJ0J76]
boolean bStop = false; //Stop identical pYi=q
FileAccessI fileAccessI = null; //File Access interface EDa08+Y
aP6%OI
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9q0,K" x)
{ -SC2Zgi)A
this.sURL = sURL; /O(;~1B
this.nStartPos = nStart; 1vR#FE?
this.nEndPos = nEnd; JG+g88
nThreadID = id; ]5)&36
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "|l oSf@
} ?GMeA}j
zx]M/=7,V#
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public void run() g)r,q&*
{ wHN`- 5%
while(nStartPos < nEndPos && !bStop) onJ[&f
{ JY050FL
Velbq
-)->Jx:{
try{ pS|JDMo
URL url = new URL(sURL); L+0N@`nRF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l<)JAT;P
httpConnection.setRequestProperty("User-Agent","NetFox"); zk^7gx3x
String sProperty = "bytes="+nStartPos+"-"; ow>[#.ua
httpConnection.setRequestProperty("RANGE",sProperty); tB(X`A.|
Utility.log(sProperty); pQgOT0f
/wCxf5q0
?H7p6mu
InputStream input = httpConnection.getInputStream(); ?;.+A4
//logResponseHead(httpConnection); dE9aE#o
{*=5qV}
"d^lS@~
byte[] b = new byte[1024]; 0?4^.N n3
int nRead; J<P/w%i2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @1qUC"Mg
{ t"74HZO>
nStartPos += fileAccessI.write(b,0,nRead); MT#[ -M\
//if(nThreadID == 1) 7zkm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K?9H.#(
} $m%/veD k
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@ :
Utility.log("Thread " + nThreadID + " is over!"); 7_'k`J@_
bDownOver = true; DkMC!Q\
//nPos = fileAccessI.write (b,0,nRead); @SVEhk#
} LM`tNZ1Fc!
catch(Exception e){e.printStackTrace ();} %!hA\S
} +P6
} m5Laq'~0_
XuAc3~HAd
Yr(f iI
//打印回应的头信息 +WEO]q?K
public void logResponseHead(HttpURLConnection con) c.me1fGn
{ v_F?x!
for(int i=1;;i++) {~p %\
{ ljR?* P
String header=con.getHeaderFieldKey(i); P9HPr2
if(header!=null) * jNu?$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _q!ck0_
Utility.log(header+" : "+con.getHeaderField(header)); B(vz$QE,$r
else %$-3fj7
break; HvfTC<+H
} 5>k~yaju/
} <HX-qNA?
[(^''*7r+T
HBkQ`T
public void splitterStop() GISI8W^
{ 6 VJj(9%
bStop = true; ,4I6RwB.
} l[j0(T
AE@Rn(1.
7&U+f:-w
} E^>7jf09,
L$07u{Q
9!OCilG
/* .;sPG
**FileAccess.java k/rkJ|i+p
*//文件访问(定位，写) {}gk4xr
package NetFox; :QY9pT
import java.io.*; Qz90 mb
oM7-1O
HOI`F3#XI
public class FileAccessI implements Serializable{ Yy:sZJ
j3'/jk]\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @ShJ:
RandomAccessFile oSavedFile; ^\t">NJ^
long nPos; C2%3+
6B P%&RL
~bQ:gArk
public FileAccessI() throws IOException 8k}CR)3@C
{ \A"a>e
this("",0); 9jFDBy+
} L.&Vi"M <@
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^O9m11
public FileAccessI(String sName,long nPos) throws IOException <}>-ip?
{ -PuVI5L<
oSavedFile = new RandomAccessFile(sName,"rw"); gM]/Y6*$b
this.nPos = nPos; \FX3=WW
oSavedFile.seek(nPos); xg!\C@$
} VH*(>^OfF
5 `mVe0uI
i; uM!d}
public synchronized int write(byte[] b,int nStart,int nLen) ;Awzm )Q
{ ;{u#~d}
int n = -1; ( I~XwP&
try{ j>=".^J
oSavedFile.write(b,nStart,nLen); (.t:sn"P
n = nLen; }{PtQc6RL!
} ~oyPmIcb
catch(IOException e) W| eG}`
{ D#(Pg
e.printStackTrace (); }=R|iz*,!
} M4]|(A
1Ee>pbd
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return n; dNmX<WXG
} M#IR=|P]
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e q.aN3KB"
} $O>MV
%[;KO&Ga
T3 /LUm
/* G4]``
**SiteInfoBean.java ?["ZEa
*/ Tdp$laPO'
package NetFox; Q 7?4GxMj
0;`PHNBq
Fsdn2{g8U
public class SiteInfoBean { !T1i_
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Zz ?y&T
private String sSiteURL; //Site's URL p`ZGV97
private String sFilePath; //Saved File's Path /FXfu
private String sFileName; //Saved File's Name eS+LFS7*k
private int nSplitter; //Count of Splited Downloading File =swcmab;
Lf<9GYNy>`
$t?e=#G
public SiteInfoBean() e1a%Rj~
{//nSplitter的缺省值为5 U%olH >1K
//default value of nSplitter is 5 8BdeqgU/_
this("","","",5); kF7Al]IgT
} Yf9L~K
W12K93tO
>.A:6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cZ,_O~
{ 6<GWDO
sSiteURL= sURL; a_x6 v*
sFilePath = sPath; 9dv~WtH>5
sFileName = sName; 247>+:7z
this.nSplitter = nSpiltter; mI18A#[ 3
8gdOQ=a
G 3x1w/L
} [\p0eUog/
hWJc A.A
IVKE dwA
public String getSSiteURL() #,pLVt<
{ )BB a
return sSiteURL; C<)&qx3
} &ICO{#v5
lDXH<W?
%;gWl1&5
public void setSSiteURL(String value) Lr&tpB<
{ {,-#;A*yW
sSiteURL = value; >skS`/6
} wm4e:&
.YlM'E*X
K ajyQ"j
public String getSFilePath() U9s y]7
{ S]a$w5ZP
return sFilePath; &!Vp'l\9
} '%4,!
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_Fjv.VQ,
public void setSFilePath(String value) >aK&T"
{ Q.yoxq
sFilePath = value; v|z1nD!?]
} i=UJ*c
}mK_d9dx
4#uoPkLK
public String getSFileName() o%iTYR:x
{ !{LwX Kf
return sFileName; PGDlSB^O
} R&A.F+Zgt
b/`'?| C
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public void setSFileName(String value) vYkoh/(/u
{ Dr<Bd;)
sFileName = value; u8QX2|
} "M]]H^r5
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Z$@Nzza-
public int getNSplitter() D1a4+AyI
{ vbU{Et\^
return nSplitter; !k^\`jMzw
} 'UKB pm/
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r+2dBp3
public void setNSplitter(int nCount) }ls>~uN
{ .u&g2Y
nSplitter = nCount; jC=_>\<|X*
} P? n`n!qZ
} $hapSrS
(H7q[UG|
Vow+,,oh
/* c2QC`h(Wb
**Utility.java C;|Ru*
*/ 2Qy&V/E ?
package NetFox; BN0))p
|{(ynZ]R
z\, w$Ef+
public class Utility { ,==lgM2V>
<ZLs+|1
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public Utility() 9b>a<Z
{ (msJ:SG
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nBd;d}LD
} Cb<\
F/h)azcn
//线程睡眠 Z q)A"'Y
public static void sleep(int nSecond) Bs*s8}6
{ 8in8_/x
try{ LdL< 5Q[
Thread.sleep(nSecond); /}wGmX! -!
} ygHNAQG~
catch(Exception e) &f$jpIyVX
{ !#QD;,SE+
e.printStackTrace (); :Fh*4 &Z
} LF8B5<[O
} H)Yv_gT
AyWCb
//日志 g_`8K,6ln
public static void log(String sMsg) ^(y4]yZ
{ U}NNbGQj
System.err.println(sMsg); >i'3\
} l\H9Io3
Z=ho7i
Z(#a-_g
public static void log(int sMsg) sy~mcH:%+
{ xJ4T7 )*
System.err.println(sMsg); iVA_a8}
} k~R_Pq S
} JP#m}W
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,+XQ!y%
/* vjWS35i
**TestMethod.java XS>4efCJ
*/ J?{uG8)
package NetFox; ?U&onGy
mY-r:
l`d=sOB^
public class TestMethod { 9,4a?.*4~
<=p"ck@
lPjgBp{/
public TestMethod() w!Z3EA;`
{ ///xx/weblogic60b2_win.exe ]>!]X*\9
try{ U`D"L4},.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =^6]N~*,D
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zk?lNs
SiteFileFetch fileFetch = new SiteFileFetch(bean); !9-dS=:Y
fileFetch.start(); L_/.b%0)
} Mb-C DPT
catch(Exception e){e.printStackTrace ();} Gz`Zp "i%0
c#_%|gg
$OmtN"
} p[cC%3
<~3@+EEM
zZkwfF
public static void main(String[] args) qk+:p]2
{ `":< ]lj
new TestMethod(); 'kp:yI7w
} |>m@]s7Z
} OA[w|Tt
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