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)); hho%~^bn(
} #Q+R%p[D
for(int i=0;i<nEndPos.length-1;i++) 0x#E4v(UA
{ 5mIXyg 0:
nEndPos = nStartPos[i+1]; \\s?B K
} vzy!3Hiw
nEndPos[nEndPos.length-1] = nFileLength; <(uTst
} 'a_s%{BJXg
} ,RN|d0dE
^H'kHl'F
A^vvST%7
//启动子线程 u*k*yWdr
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =LqL@5Xr
for(int i=0;i<nStartPos.length;i++) `oPLl0
{ aH^{Vv$]M@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tQf!|]#J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^Fvr f`A'
nStartPos,nEndPos,i); T^NJ4L4#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @#CF".fuN>
fileSplitterFetch.start(); bqNLkw#
} kxy]vH6m
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), id4]|jb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qm}\?_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5%'S
nEndPos = " + nFileLength); 1gk0l'.z
// fileSplitterFetch[nPos.length-1].start(); x Ty7lfSe
N6BNzN}-P
*k[kV
//等待子线程结束 _Z.;u0Zp8
//int count = 0; khS/'b
//是否结束while循环 .t:DvB
boolean breakWhile = false; bN!u}DnN
p_gA/. v=
4JSZ0:O
while(!bStop) Kt6C43]7
{ )^(P@D.L
write_nPos(); 6d};|#}
Utility.sleep(500); 8.-S$^hj~6
breakWhile = true; nHVPMi>
h,.fM}=H
? KF=W
for(int i=0;i<nStartPos.length;i++) ;,v.(Z ic
{ !c."
if(!fileSplitterFetch.bDownOver) <L2GUX36#
{ -O /T?H
breakWhile = false; "Whwc
break; 9PCa*,
} q /:T1a7!
} <H-tZDh5
if(breakWhile) _r[r8MB
break; sU0Stg8&b
hw|t8 ShW
k_BSY=$e*D
//count++; 3Mxz_~
//if(count>4) g@}6N.]#
// siteStop(); _ Q{T';
} -Sp/fjlq/
C|9[Al
=!YP$hfY
System.err.println("文件下载结束！"); i<bxc
} 5U3qr*/;m
catch(Exception e){e.printStackTrace ();} r:.6"VQu}
} U(P:Je
Z$1.^H.Db
I}rGx
//获得文件长度 h&q=I.3O|?
public long getFileSize() b24di
{ wFp~
int nFileLength = -1; 2*Va9HP!q
try{ f@h2;An$w
URL url = new URL(siteInfoBean.getSSiteURL()); ['?^>jfr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gh'kUZG a
httpConnection.setRequestProperty("User-Agent","NetFox"); xSdN5RN
K_Z+]]$#
E`(5UF*>
int responseCode=httpConnection.getResponseCode(); @|E;}:?u
if(responseCode>=400) \u{Jf'g
{ R !Fx)xj
processErrorCode(responseCode); Kyu@>9Ok
return -2; //-2 represent access is error An/>05|
} 9}.,2JE
j6RJC
WI0QLR'
String sHeader; tI"wVr
h)7v1,;w'
+<GrRYbC
for(int i=1;;i++) }+*w.X}L
{ ]&' jP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mn(/E/
//Utility.log(in.readLine()); PIgGXNo
sHeader=httpConnection.getHeaderFieldKey(i); U 7EHBW
if(sHeader!=null) Bl=nj.g
{ ,n^TN{#
if(sHeader.equals("Content-Length")) -e &$,R>;
{ @;g`+:=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); sE^ns\&QP=
break; 23)F-.C}j
} E1^aAlVSD
} ~Ry $>n*/
else o*?[_{xW
break; )o86lH"z
} P_kaIPP
} -hQ96S8
catch(IOException e){e.printStackTrace ();} =_K%$y*
catch(Exception e){e.printStackTrace ();} IES41y<
8y-e+
jkZ_c!
Utility.log(nFileLength); ,:c:6Y^
gkSGRshf
LQ~LB'L
return nFileLength; ^xzE^"G6
} an-\k*w
FP.(E9
!1D%-=dWX
//保存下载信息（文件指针位置） 32M6EEmPG
private void write_nPos() un.G6|S
{ =%Q\*xaR.W
try{ zNNzsT8na
output = new DataOutputStream(new FileOutputStream(tmpFile)); eL>K2Jxq
output.writeInt(nStartPos.length); Z'voCWCd
for(int i=0;i<nStartPos.length;i++) bMSD/L
{ 8W(<q|t
// output.writeLong(nPos); ,G916J*XA
output.writeLong(fileSplitterFetch.nStartPos); jK& Nkp
output.writeLong(fileSplitterFetch.nEndPos); iSnIBs9\
} Kh>?!`lL
output.close(); 0*37D5jH
} 3FGbQ_
catch(IOException e){e.printStackTrace ();} #k"1wSx16
catch(Exception e){e.printStackTrace ();} 516VQ<?B
} \a{Aa
B)(p9]q
nwZ[Ygl|
//读取保存的下载信息（文件指针位置） c2tEz&=G
private void read_nPos() ~r(g|?}P
{ _bN))9 3
try{ <1ztj#B
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !O 0ZD4/{4
int nCount = input.readInt(); 34"{rMbQ
nStartPos = new long[nCount]; ?q+8 /2
nEndPos = new long[nCount]; :7HVBH
for(int i=0;i<nStartPos.length;i++) gubb .EY
{ =YS!soO
nStartPos = input.readLong(); ]hCWe0F
nEndPos = input.readLong(); 9nP*N`
} daaga}]d
input.close(); U)&H.^@r$
} $M:4\E5(
catch(IOException e){e.printStackTrace ();} [V!^\g\6
catch(Exception e){e.printStackTrace ();} Ws2prh^e(
} 9OrA9r
FE$M[^1_
9$B)hrJo
private void processErrorCode(int nErrorCode) WyKUvVi
{ H}u)%qY+~
System.err.println("Error Code : " + nErrorCode); F?yh23&_4
} e["Z!D_H
GE/IaLo
jUV#HT
//停止文件下载 r< d?
public void siteStop() $ioaunQKP
{ GV `idFd
bStop = true; &-EyM*:u!
for(int i=0;i<nStartPos.length;i++) B`'}&6jr.
fileSplitterFetch.splitterStop(); T>AI0R3
m)tI
6/p]jN
} |q1b8A\
} KDNTnA1c
//负责部分文件的抓取 KD[)O7hYC
**FileSplitterFetch.java aufcd57
*/ b;&Yw-\nZ;
package NetFox; `Gy>tD.#V-
XnNOj>!
Z_eqM4{
import java.io.*; #R"9)vHp
import java.net.*; S4@117z5
yKX:Z4I/
vZ1D3ytfG
public class FileSplitterFetch extends Thread { s5_1}KKCs
^^j|0qshL
J8`1V`$
String sURL; //File URL tA;ZW2$#
long nStartPos; //File Snippet Start Position bKZAJLnd
long nEndPos; //File Snippet End Position (+]Ig> t
int nThreadID; //Thread's ID 3RTB~K8:{
boolean bDownOver = false; //Downing is over W2X+NacD
boolean bStop = false; //Stop identical }[hDg6i
FileAccessI fileAccessI = null; //File Access interface Aw_R $
AR[M8RA
YV2pERl
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A61-AwvF8-
{ *`\4j*$^
this.sURL = sURL; 0*]<RM
this.nStartPos = nStart; qZyt>SAx
this.nEndPos = nEnd; y7}~T!UyfF
nThreadID = id; $AL|d[[T[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 IAt+S-q0
} N8/Au=De_
rsq'60
H7cRWB
public void run() NZi'eZ{^`
{ 2yVGEp^
while(nStartPos < nEndPos && !bStop) BhhK|U/
{ .[eSKtbc)
0lJBtk9wn
N|^!"/
try{ 5u=U--
URL url = new URL(sURL); st1M.}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r(/P||`l
httpConnection.setRequestProperty("User-Agent","NetFox"); :u|UVp5
String sProperty = "bytes="+nStartPos+"-"; *SAcH_I2$>
httpConnection.setRequestProperty("RANGE",sProperty); HjETinm"
Utility.log(sProperty); J[_?>YJ
4=#QN
E!(`275s
InputStream input = httpConnection.getInputStream(); CsQ}P)
//logResponseHead(httpConnection); _#\5]D~""
z;@S_0M,Z
#f jX|b
byte[] b = new byte[1024]; 3`C3+
int nRead; Ov{B-zCA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) J3!k*"P
{ f|HgLFx
nStartPos += fileAccessI.write(b,0,nRead); vr]dRStr
//if(nThreadID == 1) :L+zUlsf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EZu
} mhHm#
::Ve,-0
n$\6}\k
Utility.log("Thread " + nThreadID + " is over!"); =}1~~
bDownOver = true; B1AF4}~5
//nPos = fileAccessI.write (b,0,nRead); RAXJsF^5o
} qgY(S}V
catch(Exception e){e.printStackTrace ();} _|2";.1E
} g]hn@{[
} rO2PbF3
fe]T9EDA
^dp[Z,[1z
//打印回应的头信息 Ni;{\"Gt
public void logResponseHead(HttpURLConnection con) nqw*oLFQ
{ &b#NF1Q.
for(int i=1;;i++) i~M.F=I5
{ {UjIxV(J
String header=con.getHeaderFieldKey(i); N'1[t
if(header!=null) ,'@ISCK^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?)ZLxLV::
Utility.log(header+" : "+con.getHeaderField(header)); ,\">ovV33
else k?_$h<Y
break; ;:K?7wfXn
} MJk:s[o
} HoQ(1e$G-
8B(Q7Qj
m$e@<~To
public void splitterStop() [E&"9%K
{ TuT=
bStop = true; @zpHemdB
} m0K2p~
"nS{ ;:
vcUM]m8k
} -1Ki7|0,
z@40g)R2A
A 5\"e^>
/* yyYbB]D
**FileAccess.java Lw78v@dY
*//文件访问(定位，写) dYttse'
package NetFox; 1 bx^Pt)
import java.io.*; O"w_sw
MDXQj5s^
Nl>b'G96
public class FileAccessI implements Serializable{ 7B>cmi
pLFL6\{g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @;-Un/'C;7
RandomAccessFile oSavedFile; nHL>}Yg
long nPos; doUqUak
kO O~%|1CP
O#ajoE
public FileAccessI() throws IOException 0DjBqh$
{ *xX0]{49q
this("",0); ;{#M
} /t2<OU9
4rCqN.J
e2H'uMy;&
public FileAccessI(String sName,long nPos) throws IOException XT;IEZQZ
{ 7UnO/K7oB.
oSavedFile = new RandomAccessFile(sName,"rw"); v?iH}7zb%Q
this.nPos = nPos; vt7C
oSavedFile.seek(nPos); :=fHPT
} 2tTV5,(1
yvnrZ&x:
a[OLS+zf!P
public synchronized int write(byte[] b,int nStart,int nLen) A&|(%
{ m_W.r+s~C4
int n = -1; uTFEI.N
try{ [aVJYr2
oSavedFile.write(b,nStart,nLen); [75e\=wK
n = nLen; XsCbJ[Z_?q
} 8YkH
catch(IOException e) i7E7%~S
{ i}12mjF
e.printStackTrace (); k{&E}:A
} =cX"gI[
X|0`$f
{.[,ee-)9
return n; v}t:}M<;
} "h|0]y^2
D+nj[8y
@G&xq"Fg7
} 04LVa|Y@U
:'Kx?Es
mr\L q~*c
/* F973U
**SiteInfoBean.java <qZ+U4@I)
*/ "U~@o4u;
package NetFox; <cd%n-
c35vjYQx0
o%s}jBo}
public class SiteInfoBean { Fd=`9N9
@g` ,'r
JaN_[ou
private String sSiteURL; //Site's URL `9NnL.w!
private String sFilePath; //Saved File's Path <OFqUp*l
private String sFileName; //Saved File's Name 23?0'AU
private int nSplitter; //Count of Splited Downloading File PW\FcT
V)?g4M3}
i(#c Yb
public SiteInfoBean() rm;"98~zJ?
{//nSplitter的缺省值为5 , X+(wp
//default value of nSplitter is 5 ed2&9E>9b
this("","","",5); LPgI"6cP
} .EELR]`y7I
M/I d\~
|I<-x)joIK
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0p2O8>w^%
{ 4B,A+{3yL
sSiteURL= sURL; uw&,pq
sFilePath = sPath; #GJh:#tt^
sFileName = sName; QiL
this.nSplitter = nSpiltter; tXuxTVhoT
Q(Y,p`>
`^Sq>R!;
} Z0@ImhejuB
]@g$<&
LR.+CxQ
public String getSSiteURL() xJ.!Q)[
{ q/G5aO*
return sSiteURL; CzbNG^+
} +u)$o
PA[Rhoit,
'Z9F0l"Nr
public void setSSiteURL(String value) +`[Sv%v&L
{ I8:&Btf
sSiteURL = value; ${2fr&Tp
} y=`(`|YW}`
2C&%UZim;P
d+)L\ `4
public String getSFilePath() |}Lgo"cTC
{ &1Iy9&y
return sFilePath; 4(gf!U
} p-Btbhv
K Hc+
e4LNnJU\|
public void setSFilePath(String value) QQcj"s
{ (HxF\#r?
sFilePath = value; ^%^0x'"
} 9jO+ew
U$Z}<8
oa7Hx<Y
public String getSFileName() MPc=cLv
{ dkC/ ?R
return sFileName; B\yq%m
} znRhQ+8;!
g>CQO,s;w
M*uG`Eo&
public void setSFileName(String value) {P+[CO
{ Puh&F< B
sFileName = value; ?Ea"%z*c5
} u{z{3fW_
'kK%sE
oPBjsQ
public int getNSplitter() x=)$sD-3
{ '& :"/4@)
return nSplitter; gV;GC{pY
} '+wTrW m~j
bc-)y3gHU
}5Uf`pM8
public void setNSplitter(int nCount) 6Fb~`J~s
{ dG+xr!
nSplitter = nCount; *@^0xz{\z
} zBfBYhS-
} [t'"4
\:7EKzQ
* vD<6qf
/* P!EX;+7+x
**Utility.java g7-K62bb
*/ 4r&~=up]
package NetFox; 2B;QS\e"
;;5i'h~?]J
kvn6 NiU
public class Utility { 470Pig>I8
DAi[3`C
t1S~~FLE
public Utility() 9~yuyv4$
{ r MlNp?{_
K%;yFEZ
7O#>N}|
} W{d/m;<@N
1\uS~RR
//线程睡眠 <Vb{QOgc;
public static void sleep(int nSecond) {{\HU0g>&
{ Z%R^;8!~
try{ #4>F%_
Thread.sleep(nSecond); XLT<,B}e
} W!*vO>^1W
catch(Exception e) AbB>ZT>hR
{ +fN0>@s
e.printStackTrace (); '>BHwc
} 0saEcJ-
} v]~[~\|a
[qB=OxH?
//日志 \BW(c)Q
public static void log(String sMsg) QR4o j
{ f`e.c_n(
System.err.println(sMsg); >Mn.|:DF]&
} R0[Gfq9M=
^Tx1y[hw$
Z/x~:u_
public static void log(int sMsg) bkTj Q
{ ojri~erJE?
System.err.println(sMsg); >B0S5:S$W
} ??PpHBJ')
} it$~uP |
65v'/m!ys
~WSC6Bh@9
/* $ }53f'QjW
**TestMethod.java 566EMy|
*/ =[kv@p
package NetFox; x& S>Mr
v]v f(]""
mwxJ#
public class TestMethod { N<x5:f#+
dq2v[?*R
c1[;a>
public TestMethod() SW7%SX,xM
{ ///xx/weblogic60b2_win.exe .kVga+la?
try{ )=[Tgh
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0U'r ia:$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <,{v>vlw
SiteFileFetch fileFetch = new SiteFileFetch(bean); R[QE:#hT
fileFetch.start(); rk|6!kry
} 0W)_5f&
catch(Exception e){e.printStackTrace ();} n !QjptQ
N@}U;x}
>:=TS"}yS}
} H\T h4teE
`8I&(k<wLe
@OpcS>:R
public static void main(String[] args) ; OsN^
{ 8'y|cF%U
new TestMethod(); (_* a4xGF
} dn Xc- <
} o9/P/PZ\X
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