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)); P"[l86:
} ) J:'5hz
for(int i=0;i<nEndPos.length-1;i++) Uzm[e%/`
{ )x5$io
nEndPos = nStartPos[i+1]; "m\UqQGX
} lMI ix0sSj
nEndPos[nEndPos.length-1] = nFileLength; d(dw]6I6
} B "s8i{Vm
} @[Jt~v
u"CIPc{Sr
1&>nL`E[3
//启动子线程 ~6Ee=NaLzP
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S]e~)IgO
for(int i=0;i<nStartPos.length;i++) +A&IxsTq5=
{ Rqd%#v
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +{ ,w#@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S'H0nJ3
nStartPos,nEndPos,i); c Gaz$=/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _|Kv~\G!
fileSplitterFetch.start(); 'AlSq:gZ
} .w*{=x0k
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oW\7q{l2)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;zxlwdfcr'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E.Gh@i
nEndPos = " + nFileLength); eG2qOq$[
// fileSplitterFetch[nPos.length-1].start(); >8{`q!=|~
XiZ Zo
2+G:04eS,e
//等待子线程结束 He$mu=$q{
//int count = 0; R'a5,zEo/
//是否结束while循环 F.* snF
boolean breakWhile = false; (J) Rs`_
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,:Ix s^-
while(!bStop) Cg%I)nz
{ PtVNG
write_nPos(); /VjbyRwV
Utility.sleep(500); )Q pP1[
breakWhile = true; :Y)kKq d
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c6}xnH
for(int i=0;i<nStartPos.length;i++) "T=3mv%S
{ |@n{tog+-
if(!fileSplitterFetch.bDownOver) :J)lC =
{ ch2e#Jf8
breakWhile = false; (nP*
break; J\8l%4q3
} N<i Vs
} VRN9yn2
if(breakWhile) /dP8F
break; |LGNoP}SA
zR/p}Wu|!
h ?qYy$
//count++; U8I~co:h
//if(count>4) aPP<W|Cmo2
// siteStop(); 2g07wJ6x
} laRKt"A
-gX2{dW
g>oYEFFJ
System.err.println("文件下载结束！"); `8b6 /
} =)UiI3xHk
catch(Exception e){e.printStackTrace ();} 01d26`G$i~
} D;8V{Hs
_ JJ0pc9t
fkUH]CdaB
//获得文件长度 nQYS{`hk
public long getFileSize() v'~nABYH
{ :phD?\!w8t
int nFileLength = -1; %a6]gsiv2<
try{ 9P>S[=
URL url = new URL(siteInfoBean.getSSiteURL()); OL9C#er
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =$z$VbBv
httpConnection.setRequestProperty("User-Agent","NetFox"); hO@v\@;r
wyhf:!-I
S2GBX1
int responseCode=httpConnection.getResponseCode(); ?g*T3S"
if(responseCode>=400) HyYQQ
{ i3WmD@
processErrorCode(responseCode); jW0z|jr
return -2; //-2 represent access is error =}o>_+"
} \ A UtGP
c\rbLr}l)
5pyvs;As
String sHeader; <T% hfW
<`p'6n79
7[<sl35
for(int i=1;;i++) &,kB7r"
{ I;4CvoT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }AfPBfgC1z
//Utility.log(in.readLine()); #CP, \G
sHeader=httpConnection.getHeaderFieldKey(i); \gQ+@O&+
if(sHeader!=null) _89G2)U=C
{ fQA)r
if(sHeader.equals("Content-Length")) umrI4.1c
{ 2o5<nGn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?4?jG3p
break; Mz.&d:
} fJlN'F7
} >!p K94
else &!~n=]*sz
break; `.-k%2?/
} m@2xC,@
} Bw7:ry
catch(IOException e){e.printStackTrace ();} %((3'le
catch(Exception e){e.printStackTrace ();} K}(n;6\
F"P:9`/
'\YhRU
Utility.log(nFileLength); $i] M6<Vxn
G[-jZ
f?^xh
return nFileLength; VCtiZ4
} tf79Gb>
fw};.M
*B}R4Y|g
//保存下载信息（文件指针位置） SF=|++b1f
private void write_nPos() Y6DiISl
{ E1v<-UPbA
try{ =w?cp}HW
output = new DataOutputStream(new FileOutputStream(tmpFile)); g]Ny?61
output.writeInt(nStartPos.length); 3VBV_/i;
for(int i=0;i<nStartPos.length;i++) H#`?toS
{ O5*uL{pvT{
// output.writeLong(nPos); =YsTF T
output.writeLong(fileSplitterFetch.nStartPos); HON[{Oq
output.writeLong(fileSplitterFetch.nEndPos); 54j $A
} 6oBt<r?CJ
output.close(); <aD+Ki6
} `7n,(
catch(IOException e){e.printStackTrace ();} .Vjpkt:H
catch(Exception e){e.printStackTrace ();} gbZX'D
} M8Lj*JN
P[oB'
CfnCi_=[`
//读取保存的下载信息（文件指针位置） ne*aC_)bT
private void read_nPos() O5%F-}(:
{ oh~Dbu=%
try{ X0=-{<W
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XArLL5_L
int nCount = input.readInt(); G ~\$Oq8
nStartPos = new long[nCount]; bFXCaD!{G
nEndPos = new long[nCount]; 41D[[Gh
for(int i=0;i<nStartPos.length;i++) nu-wQr
{ HJrg
nStartPos = input.readLong(); Om{ML,d
nEndPos = input.readLong(); ;BvWU\!
} =S +:qk
input.close(); Jev.o]|_,
} R:<AR.)K
catch(IOException e){e.printStackTrace ();} z<=t3dj
catch(Exception e){e.printStackTrace ();} 1S#bV} !
} u8=|{)yL
4"=pcHNV
I2Q?7p
private void processErrorCode(int nErrorCode) zwHsdB=v
{ g8yZc}4
System.err.println("Error Code : " + nErrorCode); \MPy"uC
} Ms3/P|{"p
YI+|6s[
7w({ GZ
//停止文件下载 (<-0UR]%q;
public void siteStop() fE}}>
{ _RVXE
bStop = true; h UDEjW@S
for(int i=0;i<nStartPos.length;i++) 014!~c
fileSplitterFetch.splitterStop(); %"V,V3kw4
%hQ`b$07t
z05pVe/5
} dGN*K}5
} @)wXP@7
//负责部分文件的抓取 c+VUk*c3
**FileSplitterFetch.java qQryv_QP
*/ Jy$-)
package NetFox; 5=e@yIr'#
c6.|; 4
<C(2(3
import java.io.*; ,)8Hl[y
import java.net.*; >MLqOUr#
=!aV?kNS8
8a1{x(\z.
public class FileSplitterFetch extends Thread { 1's^W
i^Q^F
KDk^)zv%!
String sURL; //File URL 9m>_qWaA
long nStartPos; //File Snippet Start Position C^'}{K
long nEndPos; //File Snippet End Position 3]A'C&
int nThreadID; //Thread's ID KxI(#}5o&
boolean bDownOver = false; //Downing is over wu3ZSLY
boolean bStop = false; //Stop identical |H49FL
FileAccessI fileAccessI = null; //File Access interface $TiAJ}:
,P]{*uqGiB
u)ItML
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 57rP@,vj
{ *{Vyt5
this.sURL = sURL; C_o.d~xm
this.nStartPos = nStart; HH+XEMP/g
this.nEndPos = nEnd; {Gy_QRsp,
nThreadID = id; 1l{n`gR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +`xp+Q
} DzMkeX
Zf! 7pM
H>?@nYP
public void run() .7q#{`K^=
{ L;;x%>
while(nStartPos < nEndPos && !bStop) &0myA_So
{ e%#f9i
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<KCgtO
try{ e5Z\v0
URL url = new URL(sURL); =W?c1EPLCx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;#*mB`
httpConnection.setRequestProperty("User-Agent","NetFox"); 7Uh}|6PU
String sProperty = "bytes="+nStartPos+"-"; <@P0sd
httpConnection.setRequestProperty("RANGE",sProperty); 0td;Ag
Utility.log(sProperty); Q{l;8MCL
<=lP6B
!G37K8&&*
InputStream input = httpConnection.getInputStream(); gKnAw+u\
//logResponseHead(httpConnection); OpfFF;"A'
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j"]%6RwM]
byte[] b = new byte[1024]; t+ @F"[j
int nRead; 0Pe.G0 #
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H}X"yLog*
{ HD|5:fAqA
nStartPos += fileAccessI.write(b,0,nRead); :Wln$L$
//if(nThreadID == 1) =KMck=#B
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .(krB%N
} <qu\q \
UqH7ec
LcXrD+ 1
Utility.log("Thread " + nThreadID + " is over!"); $%<gp@Gz
bDownOver = true; H!N,PI?rn
//nPos = fileAccessI.write (b,0,nRead); afjC~}
} x!J L9
catch(Exception e){e.printStackTrace ();} =e63>*M|
} F+X3CB,f
} QJ QQ-
a^N/N5-Z
[Z1EjeX
//打印回应的头信息 t{ 'QMX
public void logResponseHead(HttpURLConnection con) a v/=x
{ ie)Qsw@
for(int i=1;;i++) 1FuChd
{ CBc}N(9
String header=con.getHeaderFieldKey(i); 8w$cj'
if(header!=null) z&eJ?wb
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jU=)4nx
Utility.log(header+" : "+con.getHeaderField(header)); drH!?0Dpg
else }I]9I _S
break; ][.1b@)qV
} 3Xy>kG}
} @{j-B IRZ0
?r/7:
RGcT
public void splitterStop() Qx:+n`$/
{ XHW{EVcF
bStop = true; z-,'W`
} 'Mg%G(3
)K}b,X`($
'lWNU
} 0GB6.Ggft
$*tuv?
BD#4=u
/* "l!"gc87
**FileAccess.java pz(clTOD:
*//文件访问(定位，写) 0X@5W$x
package NetFox; F"LT\7yjyG
import java.io.*; `ul"D%
8`*(lKiL
4;_.|!LN
public class FileAccessI implements Serializable{ Q)v8hNyUmA
sQR;!-j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]O 2_&cs
RandomAccessFile oSavedFile; T_r[#j
long nPos; *rWE.4=&
0KEytm]
q.#aeqKBP
public FileAccessI() throws IOException ,L`qV
{ L&eO?I=,
this("",0); n^'{{@&(v
} H94$Xi"Bd
9[:nWp^
/wmJMX
public FileAccessI(String sName,long nPos) throws IOException 9t=erhUr
{ kG%<5QH
oSavedFile = new RandomAccessFile(sName,"rw"); 4*'NpqC(_
this.nPos = nPos; H~ (I
oSavedFile.seek(nPos); "<=^Sm
} bju0l[;=
S6cSeRmw
I@.qon2V
public synchronized int write(byte[] b,int nStart,int nLen) KExfa4W 3{
{ &%^[2^H8"
int n = -1; z8A`BVqI
try{ 6~^+</?
oSavedFile.write(b,nStart,nLen); 7%JXVP}A
n = nLen; W0R6<- 1
} Y~Zg^x2
catch(IOException e) lVMAab
{ B} &C h
e.printStackTrace (); h$lY,7
} \2W( >_z
T `N(=T^*
Xa-]+_?Q
return n; )U8F6GIC&}
} |]Ockg[
vhT9#) HI
4iDo.1B"
} !zD| @sX{
GlVq<RG*
`,TPd ~#~
/* 0ro)e~_@*
**SiteInfoBean.java 3fpX
*/ GJ!usv u
package NetFox; G.L4l|%W
{Ke3
i^j{l_-JE
public class SiteInfoBean { W&GDE
x'}{^'}/
d d8^V_Kx
private String sSiteURL; //Site's URL 5C/u`{4]Hg
private String sFilePath; //Saved File's Path >4bOM@[]
private String sFileName; //Saved File's Name ZSxKk6n}J
private int nSplitter; //Count of Splited Downloading File WC}mt%H*O
n_iq85
x}72jJe`
public SiteInfoBean() t,+p!"MRY
{//nSplitter的缺省值为5 NH4EsV]
//default value of nSplitter is 5 J\#6U|a""u
this("","","",5); jt?R a1Z
} z^~fVl
Zuwd(q
BC&Et62*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g~N)~]0{
{ ~KEnZa0
sSiteURL= sURL; U edh4qa
sFilePath = sPath; D,]m7yFT
sFileName = sName; &AA u:
this.nSplitter = nSpiltter; MiN68x9
Ro?yCy:L'
0p![&O
} IgZX,4i=o
|qfnbi-\
D`iWf3a.
public String getSSiteURL() L[<MBgFKv
{ SrU,-mA W
return sSiteURL; OpYq qBf_
} 2uV=kqnO
:y0'[LV
iQ~cG[6
public void setSSiteURL(String value) DtyT8kr
{ hnL(~
sSiteURL = value; %kKtPrT
} jUdW o}/
&9IMZAo
BYP,}yzA
public String getSFilePath() !dGy"-i$h
{ 1 BVivEG
return sFilePath; ;z!~-ByzL
} 2x'JR yef
to+jQ9q8
0G;RMR':5
public void setSFilePath(String value) ai#0ZgO
{ ^h=;]vxO
sFilePath = value; 65qH
} v='7.A
eRC@b^~
mii9eZ
public String getSFileName() IN),Lu0K
{ {U7j
return sFileName; X2Y-TET
} amgYr$)m
NcRY Ch
6SW:'u|90
public void setSFileName(String value) SbrBlP:G
{ liPUK#
sFileName = value; ^hTq~"
} YgrBIul
'^}l|(
Ch^Al2)=
public int getNSplitter() G,$RsP
{ %;9wToyK>
return nSplitter; |\Jpjm)?
} 2~~Q NWN
z&9vKF
w9l)=[s=
public void setNSplitter(int nCount) ?zKDPBj
{ *}cF]8c5W
nSplitter = nCount; m3K8hL/
} n+j'FfSz
} 7J7uHl`yq`
Q{V|{yV^y
T<?JL.8g_
/* (N0G[(>
**Utility.java *}A J7]
*/ |_ E)2b:h
package NetFox; !&ac}uD^g
.u)Po;e`
pgfI1`h
public class Utility { tb^3-ZUb
XEY((VL0
zEpcJHI%
public Utility() 9kQ~)4#
{ ,`)!K}2
Sh}AGNE'
GYyP+7K4l[
} r4D6g>)h1q
l^WFMeMD3a
//线程睡眠 ,B h[jb`y
public static void sleep(int nSecond) )#M*@e$k
{ Ga"$_DyM
try{ 5}E8Tl
Thread.sleep(nSecond); HmAA?J}
} mS0*%[S {
catch(Exception e) ?UQE;0 B
{ ,d@.@a] `
e.printStackTrace (); >/eQjp?:
} @ 4j#X
} {pm>F}Cwy
]7fqVOiOu
//日志 J'.U+XU
public static void log(String sMsg) S_ e }>-
{ V<?t(_Y
System.err.println(sMsg); sq\oatMw[
} LKFL2|af
x$?{)EY
J$v0
public static void log(int sMsg) wYOSaGyZ0I
{ [D^KM|I%+
System.err.println(sMsg); (KK9/k
} 7P.C~,+D%P
} YSs9BF:a
lX;2~iW{/
Nq"/:3@4
/* xW#r)aN]p
**TestMethod.java 2_R'Kl![
*/ N?ky2wG
package NetFox; 8 U B?X
wBA[L}
m+s^K{k}
public class TestMethod { CT6a
Lg sQz(-
}pTy mAN
public TestMethod() *U)!9DvA
{ ///xx/weblogic60b2_win.exe h7wm xa;
try{ v;80RjPy>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /~K-0K#w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $7T3wv9
SiteFileFetch fileFetch = new SiteFileFetch(bean); A|O7W|"W
fileFetch.start(); x{6/di
} }2|>Y[v2j
catch(Exception e){e.printStackTrace ();} rH8w||S2U
hmHm;l
!dv
} CY<,p$
o>';-} E
2$jTj<.K
public static void main(String[] args) w q% 4'(
{ >u4%s7v
new TestMethod(); CVyqr_n65/
} +>@<'YI<
} EdhT;!
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